CN111630262B - Engine control method and engine system - Google Patents
Engine control method and engine system Download PDFInfo
- Publication number
- CN111630262B CN111630262B CN201980009319.1A CN201980009319A CN111630262B CN 111630262 B CN111630262 B CN 111630262B CN 201980009319 A CN201980009319 A CN 201980009319A CN 111630262 B CN111630262 B CN 111630262B
- Authority
- CN
- China
- Prior art keywords
- air
- fuel ratio
- engine
- mode
- combustion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 94
- 239000000446 fuel Substances 0.000 claims abstract description 577
- 238000002485 combustion reaction Methods 0.000 claims abstract description 403
- 239000000203 mixture Substances 0.000 claims abstract description 106
- 230000009467 reduction Effects 0.000 claims abstract description 97
- 230000007423 decrease Effects 0.000 claims abstract description 33
- 238000002347 injection Methods 0.000 claims description 63
- 239000007924 injection Substances 0.000 claims description 63
- 230000000979 retarding effect Effects 0.000 claims description 18
- 238000001514 detection method Methods 0.000 claims description 17
- 230000003247 decreasing effect Effects 0.000 claims description 15
- 230000001629 suppression Effects 0.000 claims description 6
- 230000004044 response Effects 0.000 claims description 4
- 230000006835 compression Effects 0.000 description 87
- 238000007906 compression Methods 0.000 description 87
- 230000008569 process Effects 0.000 description 28
- 239000007789 gas Substances 0.000 description 15
- 230000007246 mechanism Effects 0.000 description 15
- 230000008859 change Effects 0.000 description 10
- 230000020169 heat generation Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 8
- 238000011144 upstream manufacturing Methods 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 101000761698 Hydrophis hardwickii Short neurotoxin 1 Proteins 0.000 description 4
- 230000001133 acceleration Effects 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 3
- 230000003111 delayed effect Effects 0.000 description 3
- 230000009257 reactivity Effects 0.000 description 3
- 230000001960 triggered effect Effects 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 230000033001 locomotion Effects 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000013618 particulate matter Substances 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 230000000994 depressogenic effect Effects 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/3011—Controlling fuel injection according to or using specific or several modes of combustion
- F02D41/3076—Controlling fuel injection according to or using specific or several modes of combustion with special conditions for selecting a mode of combustion, e.g. for starting, for diagnosing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D37/00—Non-electrical conjoint control of two or more functions of engines, not otherwise provided for
- F02D37/02—Non-electrical conjoint control of two or more functions of engines, not otherwise provided for one of the functions being ignition
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/3011—Controlling fuel injection according to or using specific or several modes of combustion
- F02D41/3017—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used
- F02D41/3035—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used a mode being the premixed charge compression-ignition mode
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/3011—Controlling fuel injection according to or using specific or several modes of combustion
- F02D41/3017—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used
- F02D41/3035—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used a mode being the premixed charge compression-ignition mode
- F02D41/3041—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used a mode being the premixed charge compression-ignition mode with means for triggering compression ignition, e.g. spark plug
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/3011—Controlling fuel injection according to or using specific or several modes of combustion
- F02D41/3064—Controlling fuel injection according to or using specific or several modes of combustion with special control during transition between modes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P5/00—Advancing or retarding ignition; Control therefor
- F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
- F02P5/045—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions combined with electronic control of other engine functions, e.g. fuel injection
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P5/00—Advancing or retarding ignition; Control therefor
- F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
- F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
- F02P5/15—Digital data processing
- F02P5/1502—Digital data processing using one central computing unit
- F02P5/1504—Digital data processing using one central computing unit with particular means during a transient phase, e.g. acceleration, deceleration, gear change
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B1/00—Engines characterised by fuel-air mixture compression
- F02B1/12—Engines characterised by fuel-air mixture compression with compression ignition
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/38—Controlling fuel injection of the high pressure type
- F02D2041/389—Controlling fuel injection of the high pressure type for injecting directly into the cylinder
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/50—Input parameters for engine control said parameters being related to the vehicle or its components
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2250/00—Engine control related to specific problems or objectives
- F02D2250/18—Control of the engine output torque
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2250/00—Engine control related to specific problems or objectives
- F02D2250/18—Control of the engine output torque
- F02D2250/21—Control of the engine output torque during a transition between engine operation modes or states
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2250/00—Engine control related to specific problems or objectives
- F02D2250/18—Control of the engine output torque
- F02D2250/26—Control of the engine output torque by applying a torque limit
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D29/00—Controlling engines, such controlling being peculiar to the devices driven thereby, the devices being other than parts or accessories essential to engine operation, e.g. controlling of engines by signals external thereto
- F02D29/02—Controlling engines, such controlling being peculiar to the devices driven thereby, the devices being other than parts or accessories essential to engine operation, e.g. controlling of engines by signals external thereto peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
- F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
- F02D35/025—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions by determining temperatures inside the cylinder, e.g. combustion temperatures
- F02D35/026—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions by determining temperatures inside the cylinder, e.g. combustion temperatures using an estimation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D41/0047—Controlling exhaust gas recirculation [EGR]
- F02D41/005—Controlling exhaust gas recirculation [EGR] according to engine operating conditions
- F02D41/0057—Specific combustion modes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D41/0047—Controlling exhaust gas recirculation [EGR]
- F02D41/006—Controlling exhaust gas recirculation [EGR] using internal EGR
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/3011—Controlling fuel injection according to or using specific or several modes of combustion
- F02D41/3064—Controlling fuel injection according to or using specific or several modes of combustion with special control during transition between modes
- F02D41/307—Controlling fuel injection according to or using specific or several modes of combustion with special control during transition between modes to avoid torque shocks
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Signal Processing (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Electrical Control Of Ignition Timing (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
Abstract
The control method of the engine of the invention comprises the following steps: a combustion mode setting step of selecting either a first combustion mode in which an air-fuel mixture is combusted by propagation of a flame or a second combustion mode in which the air-fuel mixture is combusted by auto-ignition; an air-fuel ratio mode setting step of selecting between a first air-fuel ratio mode leaner than a stoichiometric air-fuel ratio and a second air-fuel ratio mode equal to the stoichiometric air-fuel ratio or richer than the stoichiometric air-fuel ratio; a reduced torque setting step of setting a torque reduction amount for reducing the torque generated by the engine, based on the steering angle of the steering wheel; and a suppressing step of suppressing a decrease in the generated torque of the engine based on the torque decrease amount set in the decrease torque setting step when the air-fuel ratio mode is being switched.
Description
Technical Field
The present invention relates to a control method for an engine in which a portion of an air-fuel mixture is SI-combusted and the remaining portion is self-ignited to CI-combust the air-fuel mixture, and an engine system to which the control method is applied, and which can change a generated torque in accordance with a steering angle.
Background
Homogeneous charge compression ignition combustion is known in which a mixture of air and gasoline fuel is sufficiently compressed in a cylinder and is caused to combust by self-ignition. In addition, the following technical scheme is also proposed: instead of combusting the entire mixture by auto-Ignition, partial Compression Ignition combustion (hereinafter referred to as "Spark Ignition controlled Compression Ignition combustion" in the present specification) is performed in which SI (Spark Ignition) combustion and CI (Compression Ignition) combustion are combined (see, for example, patent document 1). In the spark ignition controlled compression ignition combustion, a part of the air-fuel mixture is forcibly combusted based on flame propagation with spark ignition as a starting point (SI combustion), and the remaining part of the unburned air-fuel mixture is combusted by self-ignition (CI combustion).
In the spark-ignition-controlled compression-ignition combustion described above, there are cases where a first air-fuel ratio mode (λ > 1) in which the formed air-fuel mixture is leaner than the stoichiometric air-fuel ratio or a second air-fuel ratio mode (λ =1 or λ < 1) in which the formed air-fuel mixture is equal to or richer than the stoichiometric air-fuel ratio is employed. The first air-fuel ratio mode can improve the thermal efficiency of the engine because the fuel is lean. The second air-fuel ratio mode is employed in a situation where priority is given to combustion stability. When the engine is operated by controlling the compression ignition combustion by the spark ignition, it is preferable to appropriately switch the mode between the first air-fuel ratio mode and the second air-fuel ratio mode in accordance with the conditions such as the engine load and the engine speed.
On the other hand, there is also known a driving assistance control (hereinafter referred to as "vehicle attitude control" in the present specification) for uniformly controlling the acceleration (G) in the front-rear direction and the width direction of the vehicle by changing the generated torque in accordance with the steering angle (see, for example, patent document 2). In the vehicle attitude control, at the moment when the driver starts turning the steering wheel, the generated torque of the engine is reduced to be lower than the required torque, and load shifting to the front wheels is generated based on the generated deceleration G. This increases the tire gripping force of the front wheel, and improves the lateral reaction force. In the vehicle attitude control, the above-described engine torque reduction is performed by, for example, retarding the ignition timing (ignition retard) at which the spark plug ignites the air-fuel mixture.
In a vehicle equipped with an engine capable of spark ignition controlled compression ignition combustion, it is sometimes required to execute vehicle attitude control. However, in a state where spark ignition control compression ignition combustion is performed and mode switching between the first air-fuel ratio mode (λ > 1) and the second air-fuel ratio mode (λ ≦ 1) is being performed, if control for reducing the engine torque for executing vehicle posture control intervenes, there is a possibility that combustion may become unstable. That is, in a state where the amount of intake air or the amount of fuel injected into the cylinder is changed to switch the air-fuel ratio mode, if the engine torque reduction control based on the ignition delay or the like is performed in a manner overlapping with this, there is a possibility that the combustion becomes unstable, and in a serious case, a misfire may occur.
Documents of the prior art
Patent literature
Patent document 1: japanese patent laid-open publication No. 2001-73775
Patent document 2: japanese patent No. 6112304
Disclosure of Invention
The present invention provides a control method for an engine capable of suppressing unstable combustion in an engine in which compression ignition combustion is controlled by spark ignition, which is combustion in which an air-fuel ratio pattern of a mixture is switched between λ >1 and λ ≦ 1, and an engine system to which the control method is applied.
A method for controlling an engine according to an aspect of the present invention is a method for controlling an engine that is mounted on a vehicle having steered wheels, mechanically coupled to drive wheels of the vehicle, and provided with an ignition plug, the method including: a combustion mode setting step of selecting a combustion mode of the engine between a first combustion mode in which all of an air-fuel mixture in a cylinder of the engine is combusted based on propagation of a flame generated by the ignition plug and a second combustion mode in which at least a part of the air-fuel mixture in the cylinder is combusted based on self-ignition, in accordance with an operation state of the engine; an air-fuel ratio mode setting step of, when the second combustion mode is selected in the combustion mode setting step, selecting an air-fuel ratio mode between a first air-fuel ratio mode and a second air-fuel ratio mode in accordance with an operating state of the engine, the first air-fuel ratio mode being a mode in which the air-fuel mixture is leaner than a stoichiometric air-fuel ratio, the second air-fuel ratio mode being a mode in which the air-fuel mixture is equal to or richer than the stoichiometric air-fuel ratio; a switching step of switching an air-fuel ratio mode according to the air-fuel ratio mode selected in the air-fuel ratio mode setting step; a reduced torque setting step of setting a torque reduction amount for reducing the torque generated by the engine, based on a steering angle of the steering wheel; and a suppressing step of suppressing a decrease in the generated torque of the engine based on the torque decrease amount set in the decrease torque setting step when the air-fuel ratio mode is being switched in the switching step.
In the engine control method according to another aspect of the present invention, a switching determination step of determining whether or not there is an air-fuel ratio mode switching request based on the air-fuel ratio mode selected in the air-fuel ratio mode setting step is performed instead of the "switching step" in the control method described above, and a suppression step of suppressing switching of the air-fuel ratio mode based on the switching request when it is determined that there is a switching request of the air-fuel ratio mode in the switching determination step when the torque reduction amount is set in the reduced torque setting step is performed instead of the "suppression step" described above.
One aspect of the present invention relates to an engine system including: an engine mounted on a vehicle having a steering wheel, mechanically coupled to a drive wheel of the vehicle, and including a spark plug; an operating state sensor that detects an operating state of the engine; a steering angle sensor that detects a steering angle of the steering wheel; and a controller; wherein the controller selects a combustion mode of the engine between a first combustion mode and a second combustion mode in accordance with a detection result of the operating condition sensor, the first combustion mode being a mode in which all of the air-fuel mixture in a cylinder of the engine is combusted based on propagation of a flame generated by the ignition plug, the second combustion mode being a mode in which at least a part of the air-fuel mixture in the cylinder is combusted based on self-ignition, the controller selects an air-fuel ratio mode between a first air-fuel ratio mode and a second air-fuel ratio mode in accordance with the operating condition of the engine when the second combustion mode is selected as the combustion mode of the engine, the first air-fuel ratio mode being a mode in which the air-fuel mixture is leaner than a stoichiometric air-fuel ratio, the second air-fuel ratio mode being a mode in which the air-fuel mixture is equal to or richer than the stoichiometric air-fuel ratio, the controller performs switching of the air-fuel ratio modes in accordance with the selected air-fuel ratio mode, the controller sets a torque reduction amount for reducing the torque of the engine in accordance with the detection result of the steering angle sensor, and the controller performs the switching of the control based on the reduced torque setting of the reduced torque.
In an engine system according to another aspect of the present invention, in place of the "air-fuel ratio mode switching control" in the engine system described above, control is performed to determine whether or not there is an air-fuel ratio mode switching request based on the selected air-fuel ratio mode, and in place of the "control to suppress a reduction in torque" described above, control is performed to suppress switching of the air-fuel ratio mode based on the switching request when it is determined that there is a switching request of the air-fuel ratio mode when the torque reduction amount is set.
Drawings
Fig. 1 is a schematic diagram of a vehicle to which an engine control method and an engine system according to the present invention are applied.
Fig. 2 is a system diagram showing the overall structure of a compression ignition engine to which the present invention is applied.
Fig. 3 is a block diagram showing a control system of the compression ignition engine.
Fig. 4 is an operation map for explaining different combustion controls according to the engine speed and load.
Fig. 5 is a timing chart for briefly explaining the combustion control performed in each region of the operation map of fig. 4.
Fig. 6 is a graph showing the heat generation rate when the spark ignition control compression ignition combustion is performed.
Fig. 7 is a time chart schematically showing a control mode in the vehicle attitude control.
Fig. 8 is a flowchart showing a specific control example of the vehicle attitude control.
Fig. 9 is a graph showing a relationship between the steering speed and the target additional deceleration.
Fig. 10A is a flowchart showing an example of the processing of the execution method of the set torque reduction.
Fig. 10B is a flowchart showing another example of the processing of the execution method of the set torque reduction.
Fig. 10C is a flowchart schematically showing an example of the engine control method according to the present invention.
Fig. 10D is a flowchart schematically showing another example of the engine control method according to the present invention.
Fig. 11 is a flowchart showing basic operations of the engine control method according to the embodiment of the present invention.
Fig. 12 is a flowchart showing details of the engine control process.
Fig. 13 is a flowchart showing details of the engine control process.
Fig. 14 is a flowchart showing details of the engine control process.
Fig. 15 is a flowchart showing details of the engine control process.
Fig. 16 is a table-format diagram showing the relationship between the operation mode and the total fuel injection amount and ignition timing.
Fig. 17 is a time chart showing a mode switching mode between the first air-fuel ratio mode (λ > 1) and the second air-fuel ratio mode (λ = 1).
Detailed Description
[ Structure of vehicle ]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, referring to fig. 1, a configuration of a vehicle 100 to which an engine control method and an engine system according to the present invention are applied will be briefly described. The vehicle 100 according to the present embodiment is an FF drive vehicle, and includes an engine main body 1 as a drive source. The engine main body 1 is an in-line four-cylinder gasoline engine having four cylinders 2 and capable of SI combustion and spark ignition controlled compression ignition combustion.
The vehicle 100 includes: a vehicle body 101 on which the engine body 1 is mounted; front wheels 102 as driving wheels and steering wheels; a rear wheel 103 as a driven wheel. The driving force generated by the engine body 1 is transmitted to the front wheels 102 via the transmission 104. Further, vehicle 100 includes: a steering mechanism 105 that steers the front wheels 102; a power steering device 106 that assists the operation of the steering gear mechanism 105. Further, vehicle 100 includes: the accelerator 107 adjusts the opening degree of a throttle valve 32, which will be described later, based on the operation by the driver.
The vehicle 100 is mounted with an ECU60 (controller) that performs electronic control of the engine main body 1. The ECU60 according to the present embodiment can execute vehicle attitude control when the driver operates the steering mechanism 105. In the vehicle attitude control, at the moment when the driver starts turning the steering mechanism 105, the generated torque of the engine main body 1 is reduced to be lower than the required torque determined by the opening degree of the accelerator 107 or the like, and the load movement to the front wheels 102 is caused based on the generated deceleration G. This increases the tire gripping force of the front wheel 102, and improves the lateral reaction force. The vehicle attitude control and the spark ignition control compression ignition combustion described above will be described in detail later.
[ Engine System ]
Next, an engine system mounted on vehicle 100 will be described. Fig. 2 is a diagram showing the overall configuration of the engine system according to the present embodiment. The engine system is provided with: an engine body 1 constituted by a four-stroke gasoline direct injection engine; an intake passage 30 through which intake air introduced into the engine body 1 flows; an exhaust passage 40 through which exhaust gas discharged from the engine body 1 flows; and an EGR device 50 that recirculates a part of the exhaust gas flowing through the exhaust passage 40 to the intake passage 30.
The engine main body 1 is used as a drive source of the vehicle 100. In the present embodiment, the engine body 1 is an engine driven by receiving a supply of fuel containing gasoline as a main component. Further, the fuel may be gasoline containing bioethanol or the like. The engine body 1 includes a cylinder block 3, a cylinder head 4, and a piston 5. The cylinder block 3 has cylinder liners forming the four cylinders 2 described above. The cylinder head 4 is attached to the upper side of the cylinder block 3, and covers the upper opening of the cylinder 2. The piston 5 is housed in each cylinder 2 so as to be slidable back and forth, and is connected to a crankshaft 7 via a connecting rod 8. The crankshaft 7 rotates around the axis in response to the reciprocating motion of the piston 5.
A combustion chamber 6 is formed above the piston 5. The fuel is supplied to the combustion chamber 6 by being injected from an injector 15 described later. The supplied mixture of fuel and air is combusted in the combustion chamber 6, and the piston 5, which is pushed down by an expansion force generated by the combustion, reciprocates in the vertical direction. The geometric compression ratio of the cylinder 2, that is, the ratio of the volume of the combustion chamber 6 when the piston 5 is positioned at the top dead center to the volume of the combustion chamber 6 when the piston 5 is positioned at the bottom dead center is set to a high compression ratio of 13 or more and 30 or less (for example, about 20) so that the spark-ignition controlled compression-ignition combustion described later becomes favorable.
A crank angle sensor SN1 and a water temperature sensor SN2 are mounted in the cylinder block 3. The crank angle sensor SN1 detects the rotation angle (crank angle) of the crankshaft 7 and the rotation speed (engine rotation speed) of the crankshaft 7. The water temperature sensor SN2 detects the temperature of the cooling water (engine water temperature) flowing through the cylinder block 3 and the cylinder head 4.
The cylinder head 4 is formed with an intake passage 9 and an exhaust passage 10 communicating with the combustion chamber 6. The bottom surface of the cylinder head 4 becomes the top surface of the combustion chamber 6. An intake side opening as a downstream end of the intake passage 9 and an exhaust side opening as an upstream end of the exhaust passage 10 are formed on the combustion chamber ceiling surface. An intake valve 11 for opening and closing the intake-side opening and an exhaust valve 12 for opening and closing the exhaust-side opening are assembled in the cylinder head 4. Although not shown, the valve type of the engine body 1 is a four-valve type with two intake valves × two exhaust valves, two intake ports 9 and two exhaust ports 10 are provided for each cylinder 2, and two intake valves 11 and two exhaust valves 12 are also provided.
The cylinder head 4 is provided with an intake-side valve gear 13 and an exhaust-side valve gear 14 including a camshaft. The intake valve 11 and the exhaust valve 12 are driven to open and close in conjunction with the rotation of the crankshaft 7 by the valve operating mechanisms 13 and 14. The intake valve operating mechanism 13 incorporates an intake VVT13a capable of changing at least the opening timing of the intake valve 11. Similarly, the exhaust valve operating mechanism 14 incorporates an exhaust VVT14a capable of changing at least the closing timing of the exhaust valve 12. Based on the control of the intake VVT13a and the exhaust VVT14a, the valve overlap period in which both the intake valve 11 and the exhaust valve 12 are opened in the exhaust top dead center front-rear range can be adjusted. Further, based on the adjustment of the valve overlap period, the amount of burned gas (internal EGR gas) remaining in the combustion chamber 6 can be adjusted.
The cylinder head 4 is also mounted with an injector 15 (fuel injection valve) and an ignition plug 16. The injector 15 injects (supplies) fuel into the cylinder 2 (combustion chamber 6). As the injector 15, a multi-nozzle type injector having a plurality of nozzle holes at its distal end portion and capable of radially injecting fuel from the nozzle holes may be employed. The injector 15 is provided so that its distal end portion is exposed in the combustion chamber 6 and faces the radially central portion of the crown surface of the piston 5.
The ignition plug 16 is disposed at a position slightly offset to the intake side with respect to the injector 15, and its distal end portion (electrode portion) is disposed at a position facing the inside of the cylinder 2. The ignition plug 16 is a forced ignition source that ignites an air-fuel mixture formed in the cylinder 2 (combustion chamber 6).
The cylinder head 4 is provided with an in-cylinder pressure sensor SN3, an intake cam angle sensor SN12, and an exhaust cam angle sensor SN13 as sensing elements. The in-cylinder pressure sensor SN3 detects the pressure of the combustion chamber 6. The intake cam angle sensor SN12 detects the rotational position of the camshaft of the intake side valve gear 13, and the exhaust cam angle sensor SN13 detects the rotational position of the camshaft of the exhaust side valve gear 14.
As shown in fig. 2, an intake passage 30 is connected to one side surface of the cylinder head 4 in such a manner as to communicate with the intake passage 9. Air (fresh air) introduced from the upstream end of the intake passage 30 is introduced into the combustion chamber 6 through the intake passage 30 and the intake passage 9. An air cleaner 31, a throttle valve 32, a supercharger 33, an electromagnetic clutch 34, an intercooler 35, and a surge tank 36 are disposed in this order from the upstream side in the intake passage 30.
The air cleaner 31 removes foreign matter in the intake air to purify the intake air. The throttle valve 32 opens and closes the intake passage 30 in conjunction with the depression of the accelerator 107 to adjust the flow rate of intake air in the intake passage 30. The supercharger 33 compresses intake air and sends the intake air to the downstream side of the intake passage 30. The supercharger 33 is mechanically coupled to the engine main body 1, and is engaged with and disengaged from the engine main body 1 by the electromagnetic clutch 34. After the electromagnetic clutch 34 is engaged, the driving force is transmitted from the engine body 1 to the supercharger 33, and the supercharger 33 supercharges the engine. The intercooler 35 cools the intake air compressed by the supercharger 33. The surge tank 36 is disposed immediately upstream of an intake manifold, not shown, and is a tank provided to equally distribute intake air to the spaces of the plurality of cylinders 2.
An air flow sensor SN4 that detects the flow rate of intake air, first and second intake air temperature sensors SN5 and SN7 that detect the temperature of intake air, and first and second intake air pressure sensors SN6 and SN8 that detect the pressure of intake air are provided at each portion of the intake passage 30. The air flow sensor SN4 and the first intake air temperature sensor SN5 are disposed in a portion between the air cleaner 31 and the throttle valve 32 in the intake passage 30, and detect the flow rate and temperature of intake air passing through the portion, respectively. The first intake air pressure sensor SN6 is provided in a portion between the throttle valve 32 and the supercharger 33 (located on the downstream side with respect to a connection port of the EGR passage 51 described later) in the intake passage 30, and detects the pressure of intake air passing through the portion. The second intake air temperature sensor SN7 is provided in a portion between the supercharger 33 and the intercooler 35 in the intake passage 30, and detects the temperature of the intake air passing through this portion. The second intake air pressure sensor SN8 is provided in the surge tank 36, and detects the pressure of intake air in the surge tank 36.
The intake passage 30 is provided with a bypass passage 38 for sending intake air to the combustion chamber 6 so as to bypass the supercharger 33. The bypass passage 38 connects the surge tank 36 and the vicinity of the downstream end of an EGR passage 51 described later to each other. The bypass duct 38 is provided with a bypass valve 39 capable of opening and closing the bypass duct 38.
The exhaust passage 40 is connected to the other side surface of the cylinder head 4 so as to communicate with the exhaust passage 10. Burned gas (exhaust gas) generated in the combustion chamber 6 is discharged to the outside of the vehicle 100 through the exhaust passage 10 and the exhaust passage 40. The exhaust passage 40 is provided with a catalytic converter 41. The catalytic converter 41 incorporates a three-way catalyst 41a for purifying harmful components (HC, CO, NOx) contained in the exhaust gas flowing through the exhaust passage 40, and a GPF (gasoline engine particulate filter) 41b for trapping Particulate Matter (PM) contained in the exhaust gas.
The EGR device 50 includes an EGR passage 51 connecting the exhaust passage 40 and the intake passage 30, and an EGR cooler 52 and an EGR valve 53 provided in the EGR passage 51. The EGR passage 51 interconnects a portion of the exhaust passage 40 on the downstream side with respect to the catalytic converter 41 and a portion of the intake passage 30 between the throttle valve 32 and the supercharger 33. The EGR cooler 52 cools the exhaust gas (external EGR gas) that flows back from the exhaust passage 40 to the intake passage 30 through the EGR passage 51 by heat exchange. The EGR valve 53 is provided at a portion of the EGR passage 51 located on the downstream side of the EGR cooler 52 so as to be openable and closable, and adjusts the flow rate of the exhaust gas flowing through the EGR passage 51. Further, the EGR passage 51 is provided with a differential pressure sensor SN9 for detecting a difference between the pressure on the upstream side and the pressure on the downstream side of the EGR valve 53.
An accelerator opening sensor SN10 (one of the operation state sensors) for detecting the opening of the accelerator is attached to the accelerator 107. The accelerator opening sensor SN10 is a sensor for detecting a state where the accelerator 107 is depressed, and is also a sensor for detecting acceleration and deceleration performed by the driver. A steering angle sensor SN11 (steering angle sensor) is attached to the steering mechanism 105. The steering angle sensor SN11 detects a steering angle at which the steering mechanism 105 steers the front wheels 102. Further, another steering angle sensor capable of detecting the steering angle of the front wheels 102 may be applied.
[ control Structure ]
Fig. 3 is a block diagram showing a control structure of the engine system. The engine system of the present embodiment is collectively controlled by an ECU (engine control module) 60. The ECU60 is a microprocessor composed of a CPU, ROM, RAM, and the like.
ECU60 receives detection signals from various sensors mounted on vehicle 100. The ECU60 is electrically connected to the crank angle sensor SN1, the water temperature sensor SN2, the in-cylinder pressure sensor SN3, the air flow sensor SN4, the first and second intake air temperature sensors SN5 and SN7, the first and second intake air pressure sensors SN6 and SN8, the differential pressure sensor SN9, the accelerator opening degree sensor SN10, the steering angle sensor SN11, the intake cam angle sensor SN12, and the exhaust cam angle sensor SN13. Information measured by these sensors SN1 to SN13, that is, information such as crank angle, engine speed, engine water temperature, in-cylinder pressure, intake air flow rate, intake air temperature, intake air pressure, differential pressure across EGR valve 53, accelerator opening degree, steering angle, cam angle of intake and exhaust, is sequentially input to ECU60.
The ECU60 performs various determinations, calculations, and the like, and controls various portions of the engine according to input signals from the above-described sensors SN1 to SN13. That is, the ECU60 is electrically connected to the intake VVT13a, the exhaust VVT14a, the injector 15, the ignition plug 16, the throttle valve 32, the electromagnetic clutch 34, the bypass valve 39, the EGR valve 53, and the like, and outputs control signals to these devices based on the results of the above calculation and the like.
The ECU60 functionally includes a combustion control unit 61, a vehicle attitude control unit 62, and a determination unit 63. The combustion control section 61 controls the fuel injection operation of the injector 15 and the ignition operation of the ignition plug 16. For example, the combustion control unit 61 determines the injection amount and injection timing of the fuel from the injector 15 and the ignition timing of the ignition plug 16 based on the engine speed detected by the crank angle sensor SN1, the engine load (required torque) determined from the opening degree of the accelerator 107 detected by the accelerator opening degree sensor SN10, and the intake air flow rate detected by the air flow sensor SN4, and drives the injector 15 and the ignition plug 16 based on these determinations. At this time, the combustion control unit 61 refers to a preset operation map (an example is shown in fig. 4) to select the combustion mode. The combustion mode includes a combustion mode (spark ignition control compression ignition combustion) in which the injector 15 and the ignition plug 16 are driven to self-ignite the air-fuel mixture in the cylinder 2 at a predetermined timing, which will be described in detail later.
The vehicle attitude control unit 62 executes vehicle attitude control for changing the generated torque of the engine main body 1 in accordance with the steering angle at which the steering mechanism 105 steers the front wheels 102 (a reduced torque setting step). For example, the vehicle attitude control unit 62 refers to the detection value of the steering angle sensor SN11, and determines that the vehicle 100 is in a turning (cornering) running state when the steering angle is increased by a predetermined amount within a predetermined time, and performs control to reduce the generated torque. The method of reducing the torque is not particularly limited, but in the present embodiment, either of retard control for retarding the ignition (driving) timing of the ignition plug 16 or amount reduction control for reducing the amount of fuel supplied into the cylinder 2 is adopted depending on the operation mode or the like. The vehicle attitude control unit 62 performs various controls so that the ignition timing is retarded or the fuel injection amount is decreased as the torque reduction amount by the vehicle attitude control is larger.
The determination unit 63 determines whether or not a state in which combustion in the combustion chamber 6 is unstable or a state in which a flame-out is likely to occur (unstable combustion state) is reached. In the present embodiment, the combustion control including the spark ignition control compression ignition combustion by the combustion control unit 61 and the vehicle posture control by the vehicle posture control unit 62 are executed in a superimposed manner. When both controls are executed in a superimposed manner under a certain condition, the above-described unstable combustion state is caused. When it is further determined that the above-described unstable combustion state is reached, the determination determining unit 63 executes control for changing the control mode of the combustion control or the vehicle attitude control.
As will be described in detail later, in the present embodiment, the air-fuel ratio mode in which the spark-ignition controlled compression-ignition combustion is performed is switched between a first air-fuel ratio mode (λ > 1) that is leaner than the stoichiometric air-fuel ratio and a second air-fuel ratio mode (λ ≦ 1) that is equal to the stoichiometric air-fuel ratio or richer than the stoichiometric air-fuel ratio, depending on the operating state (an air-fuel ratio mode setting step and a switching step). When the torque reduction control by the vehicle posture control is performed in a superimposed manner during the switching of the air-fuel ratio mode, an unstable combustion state is caused. In this regard, the determination unit 63 gives an instruction to the combustion control unit 61 or the vehicle attitude control unit 62 to suppress execution of the vehicle attitude control when the switching of the air-fuel ratio mode is being performed, or an instruction to suppress switching of the air-fuel ratio mode when the vehicle attitude control is being performed (suppressing step).
[ Combustion control ]
Next, the combustion control performed by the combustion control unit 61 will be described in detail. Fig. 4 is a simple operation map for explaining different combustion controls according to the engine speed and load. The operation map shows four operation regions: a first area A1, a second area A2, a third area A3, and a fourth area A4. The first region A1 is a low-load region where the engine load is low (including no load) in a region where the engine speed is low and medium, and a medium-load and high-load region in a region where the engine speed is high. The second region A2 is a region of higher load than the first region A1 in the low-speed/medium-speed region (low-speed/medium-load region). The third region A3 is a region (low speed/medium speed/high load region) in which the load is higher in the low speed/medium speed region than in the second region A2. The fourth region A4 is a region close to the maximum load line in the low speed region.
SI combustion is performed in the first region A1 and the fourth region A4 (first combustion mode). The SI combustion is a combustion mode in which the air-fuel mixture in the combustion chamber 6 is ignited by spark ignition using the ignition plug 16, and a flame spreading from the ignition point to the surroundings in a combustion region is propagated to forcibly combust the air-fuel mixture. That is, a combustion mode in which all the air-fuel mixture in the cylinder 2 is combusted based on propagation of flame generated by the ignition plug 16.
Spark ignition control compression ignition combustion is performed in the second region A2 and the third region A3 (second combustion mode). The spark ignition controlled compression ignition combustion is combustion in which the above-described SI combustion and CI combustion are mixed. CI combustion is a combustion mode in which the air-fuel mixture is compressed by the piston 5 and burned by self-ignition in an environment of high temperature and high pressure. Spark ignition controlled compression ignition combustion is a combustion regime as follows: spark ignition is performed in an environment immediately before the air-fuel mixture is self-ignited to perform SI combustion of a part of the air-fuel mixture in the combustion chamber 6, and after the SI combustion (further high temperature and high pressure due to the SI combustion), the remaining air-fuel mixture in the combustion chamber 6 is self-ignited to perform CI combustion. That is, a combustion mode in which at least a portion of the air-fuel mixture in the cylinder 2 is combusted based on self-ignition.
In the present embodiment, in the spark ignition controlled compression ignition combustion, the air-fuel mixture formed in the combustion chamber 6 has: a first air-fuel ratio mode (λ > 1) that is leaner than the stoichiometric air-fuel ratio; and a second air-fuel ratio mode (lambda < 1) that is equal to or richer than the stoichiometric air-fuel ratio. Specifically, the first air-fuel ratio mode is a mode in which spark-ignition controlled compression-ignition combustion is performed when the air-fuel ratio (a/F), which is the weight ratio of air (fresh air) to fuel in the combustion chamber 6, is set to a value greater than the stoichiometric air-fuel ratio (14.7). On the other hand, the second air-fuel ratio mode is a mode in which spark-ignition controlled compression-ignition combustion is performed when the air-fuel ratio is set equal to the stoichiometric air-fuel ratio (λ = 1) or in the vicinity thereof (λ < 1). In the present embodiment, the air-fuel ratio a/F of the mixture formed in the first air-fuel ratio mode is set in a range of about 25 to 30/1 (first air-fuel ratio range). The air-fuel ratio a/F of the second air-fuel ratio mode is undoubtedly 14.7/1 of λ =1 (second air-fuel ratio range). In the spark ignition control compression ignition combustion, either one of the first air-fuel ratio mode (λ > 1) and the second air-fuel ratio mode (λ ≦ 1) is selected in accordance with the operating state of the engine (air-fuel ratio mode setting step).
Fig. 5 is a timing chart for briefly explaining the combustion control performed in each of the regions A1 to A4 of the operation map of fig. 4. Fig. 5 (a) shows the fuel injection timing, ignition timing, and combustion pattern (heat generation rate waveform) when the engine is operated at the operating point P1 included in the second region A2 shown in fig. 4. Combustion in the above-described first air-fuel ratio mode (λ > 1) in spark ignition controlled compression ignition combustion is performed in the second region A2.
At this operating point P1, the combustion control performed by the combustion control unit 61 is as follows. As shown in the drawing (a), the injector 15 injects the fuel in two separate injections, i.e., a first injection and a second injection, during a period from the middle to the end of the compression stroke. At a time near compression top dead center and on a slightly advanced side, the spark plug 16 is caused to ignite the air-fuel mixture. The spark ignition control starts compression ignition combustion when this ignition is triggered, a part of the air-fuel mixture in the combustion chamber 6 is combusted by flame propagation (SI combustion), and thereafter the rest of the air-fuel mixture is combusted by self-ignition (CI combustion).
The advantages of spark ignition controlled compression ignition combustion are described with reference to fig. 6. Fig. 6 is a graph showing the heat generation rate when the spark ignition control compression ignition combustion is performed. The following properties are possessed in spark ignition controlled compression ignition combustion: heat release is more acute when CI combustion is present than when SI combustion is present. That is, as shown in fig. 6, the rising gradient at the initial stage of combustion corresponding to the SI combustion is smaller than the rising gradient occurring at the subsequent CI combustion. When the temperature and pressure in the combustion chamber 6 are increased by the SI combustion, the unburned gas-fuel mixture is self-ignited to start the CI combustion. At the time of the start of CI combustion (inflection point X = crank angle θ CI in fig. 6), the gradient of the heat generation rate waveform changes from small to large. In the spark ignition controlled compression ignition combustion, in accordance with such a tendency of the heat generation rate, the rate of pressure increase (dp/d θ) in the combustion chamber 6 generated at the time of SI combustion is smaller than that at the time of CI combustion.
After the CI combustion is started, the SI combustion is performed concurrently with the CI combustion. Since the combustion speed of the mixture burned in CI is faster than that in SI, the heat release rate becomes relatively large. However, since CI combustion is exhibited after compression top dead center, the inclination of the heat release rate waveform does not become excessively large. That is, after the compression top dead center is passed, the piston 5 is lowered to lower the operating pressure, which suppresses an increase in the heat generation rate, and as a result, avoids the dp/d θ at the time of CI combustion becoming excessively large. In this way, in the spark-ignition-controlled compression-ignition combustion, based on the property that CI combustion is performed after SI combustion, dp/d θ, which is an index of combustion noise, is difficult to become excessively large, and combustion noise can be suppressed as compared with simple CI combustion (in the case where all fuel is CI-combusted).
With the end of CI combustion, spark ignition controlled compression ignition combustion also ends. Since CI combustion is faster than SI combustion, the combustion end period can be made earlier than in SI combustion alone (in the case where all the fuel is SI-combusted). In other words, in the spark ignition controlled compression ignition combustion, the combustion end timing can be made close to the compression top dead center in the expansion stroke. As a result, in the spark-ignition controlled compression-ignition combustion, the fuel economy can be improved as compared with the simple SI combustion.
Returning to fig. 5, the diagram (b) shows the mode of combustion control by the combustion control unit 61 when the engine is operated at the operating point P2 (a point in the region of low load in the third region A3) included in the third region A3 shown in fig. 4. In the spark-ignition controlled compression-ignition combustion performed in the low load region in the third region A3, combustion of the air-fuel mixture that is in the range of the second air-fuel ratio pattern (λ ≦ 1) and is adjusted to λ =1 is performed.
At the operating point P2, the combustion control section 61 causes the injector 15 to perform a first fuel injection for injecting a relatively large amount of fuel in the intake stroke, and then to perform a second fuel injection for injecting a smaller amount of fuel than the first fuel injection in the compression stroke. The combustion control unit 61 causes the ignition plug 16 to ignite the air-fuel mixture at a timing slightly advanced from the compression top dead center. The spark ignition control compression ignition combustion is started when the ignition is started, as in the case of the above-described operating point P1.
Fig. 5 (c) shows an aspect of the combustion control performed by the combustion control unit 61 when the engine is operated at the operating point P3 included in the third region A3 (a point in the region of a high load in the third region A3). In the high load region of the third region A3, control is performed to perform spark ignition control compression ignition combustion of the air-fuel mixture that is set to have the air-fuel ratio in the combustion chamber 6 slightly richer than the stoichiometric air-fuel ratio (λ ≦ 1).
At the operating point P3, the combustion control section 61 causes the injector 15 to inject all or most of the fuel to be injected in one cycle in the intake stroke. For example, as shown in (c), fuel is injected in a continuous period from the latter half of the intake stroke to the initial stage of the compression stroke. The combustion control unit 61 causes the ignition plug 16 to ignite the air-fuel mixture at a timing near the compression top dead center and on the slightly retarded side. The spark ignition control compression ignition combustion is started when the ignition is started, as in the case of the above-described operating points P1 and P2.
Here, an example is shown in which the third region A3 is divided by load into a case where the air-fuel mixture is formed with λ =1, which is the stoichiometric air-fuel ratio, and a case where the air-fuel mixture is formed with λ ≦ 1, which is slightly richer than the stoichiometric air-fuel ratio. Alternatively, the air-fuel mixture may be formed at λ =1 of the stoichiometric air-fuel ratio in the entire third region A3. In the embodiment described later, the second air-fuel ratio mode executed in the third region A3 will be described as a mode in which the air-fuel mixture with λ =1 is subjected to spark-ignition controlled compression-ignition combustion.
Fig. 5 (d) shows a combustion control mode performed by the combustion control unit 61 when the engine is operated at the operating point P4 included in the fourth region A4 with a low rotation speed and a high load. In the fourth region A4, spark ignition control compression ignition combustion is not performed, but SI combustion (retard-SI) in which the ignition timing is retarded is performed.
At the operating point P4, the combustion control portion 61 causes the injector 15 to perform a first fuel injection injecting a relatively large amount of fuel in the intake stroke, and then causes the injector to perform a second fuel injection injecting a smaller amount of fuel than the first fuel injection in the latter stage of the compression stroke (immediately before the compression top dead center). Further, the combustion control section 61 causes the ignition plug 16 to perform retarded ignition. The ignition timing for the air-fuel mixture is set to a relatively late timing after about 5 to 20 ° CA from the compression top dead center, for example. SI combustion starts when this ignition is triggered, and all the air-fuel mixture in the combustion chamber 6 burns due to flame propagation. The ignition timing in the fourth region A4 is set at the retarded angle as described above in order to prevent abnormal combustion such as knocking or preignition.
Fig. 5 (e) shows a mode of combustion control by the combustion control unit 61 when the engine is operated at the operating point P5 included in the high load and high rotation region in the first region A1. In the first region A1, spark ignition control compression ignition combustion is not performed and normal SI combustion (intake-SI) is performed.
At the operating point P5, the combustion control section 61 causes the injector 15 to inject fuel for one continuous period from the intake stroke to the compression stroke. Since the operating point P5 is a condition of high load and high rotation speed, the amount of fuel to be injected in one cycle is inherently large, and the crank angle period necessary for injecting the required amount of fuel is long. Further, in the medium-low load region of the first region A1, the fuel injection amount is reduced to an amount lower than that of the (e) map. The combustion control unit 61 causes the ignition plug 16 to ignite the air-fuel mixture at a timing slightly advanced from the compression top dead center. The SI combustion starts when this ignition is triggered, and all the air-fuel mixtures in the combustion chamber 6 burn due to flame propagation.
[ vehicle attitude control ]
Next, the vehicle attitude control executed by the vehicle attitude control unit 62 will be described in detail. Fig. 7 is a time chart schematically showing a control mode of the vehicle attitude control according to the present embodiment. Fig. 7 shows a relationship between the steering angle at which the steering mechanism 105 steers the front wheels 102, the deceleration of the vehicle 100 based on the vehicle posture control, and the generated torque for realizing the deceleration.
When the amount of change in the steering angle of the steering mechanism 105 detected by the steering angle sensor SN11 is equal to or greater than a predetermined reference amount of change (the steering speed is equal to or greater than a predetermined value), the vehicle attitude control unit 62 gradually increases the deceleration as the vehicle 100 is turning. As described above, in the present embodiment, the torque generated by the engine main body 1 is reduced by retard control of the ignition timing of the ignition plug 16 or reduction control of the fuel supplied into the cylinder 2, whereby the driving force of the vehicle 100 is reduced and the deceleration is increased.
Specifically, the vehicle posture control unit 62 reduces the engine torque, which is a target basic engine torque determined based on the vehicle speed detected by the crank angle sensor SN1 and the opening degree of the accelerator 107 detected by the accelerator opening degree sensor SN10, so that the engine torque becomes smaller than the required engine torque during the normal operation. Further, the vehicle attitude control portion 62 gradually decreases the deceleration when the steering speed is less than the specified value. In this way, the lateral reaction force of the front wheels 102 can be increased during cornering, and the vehicle 100 can be smoothly turned.
A specific control example of the vehicle attitude control will be described with reference to a flowchart shown in fig. 8. In fig. 8, the vehicle posture control is referred to as "additional deceleration setting processing" as meaning that deceleration is added by torque reduction of the target base engine torque. After the additional deceleration setting process is started, the vehicle attitude control unit 62 determines whether or not the absolute value of the steering angle obtained based on the detection result of the steering angle sensor SN11 is increasing (step # 1). When the absolute value of the steering angle is increasing (yes in step # 1), the vehicle attitude control unit 62 calculates the steering speed from the steering angle obtained as described above (step # 2).
Next, the vehicle attitude control unit 62 determines whether or not the absolute value of the steering speed determined in step # 2 is decreasing (step # 3). In the case where the absolute value of the steering speed is not decreasing (yes in step # 3), that is, in the case where the absolute value of the steering speed is increasing or the absolute value of the steering speed is not changing, the vehicle attitude control portion 62 sets the target additional deceleration in accordance with the steering speed (step # 4). The target additional deceleration is a deceleration that should be added to the vehicle 100 according to the operation of the steering mechanism 105 intended by the driver.
Specifically, the vehicle attitude control unit 62 obtains the target additional deceleration corresponding to the steering speed calculated in step # 2, based on the relationship between the target additional deceleration and the steering speed shown in the map of fig. 9. Referring to fig. 9, when the steering speed is equal to or less than a predetermined threshold value Ts, the corresponding target additional deceleration is 0. That is, when the steering speed is equal to or lower than the threshold value Ts, the vehicle attitude control unit 62 does not execute control (vehicle attitude control) for reducing the engine torque in order to apply deceleration to the vehicle 100 even if the steering operation of the steering mechanism 105 is performed. On the other hand, when the steering speed exceeds the threshold value Ts, the target additional deceleration corresponding to the steering speed gradually approaches the predetermined upper limit value Dmax (for example, 1 m/s) as the steering speed increases 2 ). That is, the target additional deceleration increases as the steering speed increases, and the increase rate of the increase amount thereof becomes smaller.
Next, the vehicle posture control unit 62 determines the maximum increase rate Rmax which is the threshold value of the additional deceleration when the deceleration is added to the vehicle 100 in the current processing. Then, the vehicle posture control unit 62 determines the additional deceleration in this processing in a range where the rate of increase of the additional deceleration is equal to or less than the maximum rate of increase Rmax (step # 5).
Specifically, when the rate of increase of the target additional deceleration set in step # 4 of the current process from the additional deceleration determined in the previous process is equal to or less than the maximum rate of increase Rmax, the vehicle posture control unit 62 determines the target additional deceleration determined in step # 4 as the additional deceleration in the current process. On the other hand, when the rate of increase of the target additional deceleration determined in step # 4 of the current processing with respect to the previous additional deceleration is greater than Rmax, the vehicle posture control unit 62 determines, as the additional deceleration in the current processing, a value obtained by increasing the previously determined additional deceleration at the rate of increase = Rmax.
If the absolute value of the steering speed is decreasing in step #3 (yes in step # 3), the vehicle posture control unit 62 determines the additional deceleration determined in the previous processing as the additional deceleration in the current processing (step # 6). That is, when the absolute value of the steering speed is reduced, the additional deceleration (maximum value of the additional deceleration) at the time when the steering speed is at the maximum is maintained.
In step # 1, if the absolute value of the steering angle is not increasing (no in step # 1), the vehicle attitude control unit 62 sets an amount (deceleration decrease amount) by which the additional deceleration determined in the previous processing is decreased in the current processing (step # 7). The deceleration reduction amount is based on a predetermined reduction rate (for example, 0.3 m/s) stored in advance in a memory or the like provided in ECU60 3 ) And is calculated. Alternatively, the deceleration reduction amount is calculated based on the operation state of vehicle 100 obtained from various sensors, the reduction rate determined in accordance with the steering speed calculated in step # 2, or the like. Then, the vehicle posture control unit 62 subtracts the deceleration reduction amount set in step # 7 from the additional deceleration determined in the previous processing, thereby determining the additional deceleration in the current processing (step # 8).
Then, the vehicle attitude control unit 62 determines a torque reduction amount based on the present additional deceleration determined in step # 5, #6, or #8 (step # 9; reduced torque setting step). Specifically, the vehicle attitude control unit 62 determines the torque reduction amount necessary to realize the additional deceleration at this time, based on the current vehicle speed, the shift position, the road surface gradient, and the like. The vehicle attitude control unit 62 executes retard control for retarding the ignition timing of the ignition plug 16 and reduction control for reducing the amount of fuel supplied into the cylinder 2 by the combustion control unit 61 in order to reduce the engine torque by a component corresponding to the determined torque reduction amount.
[ switching control of execution method of Torque reduction ]
As described above, the engine body 1 of the present embodiment is configured to execute the vehicle attitude control for reducing the generated torque of the engine body 1 when the amount of change per unit time of the steering angle is equal to or larger than the preset reference amount of change (hereinafter referred to as "satisfaction of the first condition"). On the other hand, the engine body 1 performs not only SI combustion (first combustion mode) but also spark ignition control compression ignition combustion (second combustion mode) as a combustion form of the air-fuel mixture in the combustion chamber 6. That is, when the required torque determined by the accelerator opening and the vehicle speed falls within the second range A2 and the third range A3 shown in fig. 4 (hereinafter, referred to as "establishment of the second condition"), the spark-ignition controlled compression-ignition combustion is executed to cause the air-fuel mixture to self-ignite at a predetermined timing. Either the SI combustion or the spark ignition controlled compression ignition combustion is selected in accordance with the operating state of the engine (combustion mode setting step).
The vehicle attitude control unit 62 executes vehicle attitude control when determining that the first condition is satisfied (see fig. 8). When determining that the second condition is satisfied, the combustion control unit 61 controls the fuel injection timing of the injector 15 and the drive (ignition) timing of the ignition plug 16 (see fig. 5) so that the spark-ignition control compression-ignition combustion is exhibited. In the spark-ignition controlled compression-ignition combustion, mode switching is performed between a first air-fuel ratio mode (λ > 1) in which the air-fuel mixture is made leaner than the stoichiometric air-fuel ratio and a second air-fuel ratio mode (λ ≦ 1) in which the air-fuel mixture is made equal to or richer than the stoichiometric air-fuel ratio (switching step; see fig. 5 (b) and (c)).
When the first condition and the second condition are satisfied at the same time, the vehicle posture control and the spark ignition control compression ignition combustion are performed so as to overlap each other. That is, in a state where the spark ignition control compression ignition combustion is being executed, the engine torque may be reduced in order to execute the vehicle posture control. The simplest method of torque reduction is to retard the ignition timing of the ignition plug 16 (ignition retard). However, when ignition retard is executed to execute vehicle attitude control while spark ignition control compression ignition combustion is being performed, there is a possibility that combustion becomes unstable. That is, if the start timing of the SI combustion in the spark ignition controlled compression ignition combustion is retarded by the ignition retard, there is a possibility that the in-cylinder pressure in the combustion chamber 6 cannot rise to the in-cylinder pressure necessary for the CI combustion in the latter half of the combustion. In this case, a state in which combustion is unstable or a state in which a flame is extinguished (unstable combustion state) may occur in the combustion chamber 6.
In view of the above, in the present embodiment, the determination unit 63 determines whether or not the operation state in which the unstable combustion state is achieved is reached. Specifically, it is determined whether the first condition and the second condition are satisfied at the same time. When it is determined that the unstable combustion state is reached, the determination unit 63 switches the engine torque reduction method for executing the vehicle posture control from the ignition delay to the amount reduction control for reducing the amount of fuel supplied into the cylinder 2. If the fuel is reduced by at least the fuel injection amount set for the required torque, the engine torque naturally decreases without performing the ignition delay. On the other hand, since the timing at which the spark plug 16 forcibly ignites the air-fuel mixture is maintained at the timing set for the spark ignition control compression ignition combustion, the SI combustion is started at the regular timing. Therefore, the specified spark ignition control compression ignition combustion can be exhibited.
The switching control of the torque reduction means by the determination unit 63 will be described with reference to the flowcharts shown in fig. 10A and 10B. The control example of fig. 10A is as follows: the method of engine torque reduction for executing the vehicle attitude control is switched depending on whether the spark ignition control is being performed or not, that is, depending on whether the engine is operating in the second region A2 or the third region A3 of the operation map of fig. 4 or not.
After the engine control process is started, ECU60 (fig. 3) reads various sensor signals relating to the operating state of vehicle 100 (step # 11). Specifically, the ECU60 acquires various information including a vehicle speed obtained from the detection value of the crank angle sensor SN1, the opening degree of the accelerator 107 detected by the accelerator opening degree sensor SN10, the steering angle of the steering mechanism 105 detected by the steering angle sensor SN11, a shift position currently set in the transmission of the vehicle 100, and the like.
Next, the determination unit 63 determines whether or not there is a request for adding deceleration, that is, whether or not there is a request for torque reduction for executing the vehicle attitude control (whether or not the first condition is satisfied) (step # 12). When the amount of increase in the steering angle exceeds the reference increase amount, the vehicle attitude control portion 62 issues a request for additional deceleration (yes in step # 12). In this case, the determination unit 63 further determines whether the combustion control unit 61 is executing spark ignition control compression ignition combustion (whether the second condition is established) (step # 13). When there is no request for additional deceleration (no in step # 12), the determination unit 63 ends the process (returns to step # 11).
When the spark ignition control compression ignition combustion is being executed (yes in step # 13), the determination unit 63 performs setting to reduce the torque for the vehicle attitude control by the vehicle attitude control unit 62 performing reduction control for reducing the fuel injection amount of the injector 15 (reduced torque setting step; step # 14). That is, when the first condition and the second condition are satisfied, the determination unit 63 performs the amount reduction control for reducing the amount of fuel supplied into the cylinder 2 in order to reduce the generated torque of the engine body 1. The degree of reduction in the fuel injection amount is set to be larger as the torque reduction amount is larger.
In contrast, when the spark ignition control compression ignition combustion is not being performed (no in step # 13), that is, when the engine is operating in the first region A1 or the fourth region A4 of the operation map of fig. 4, the determination unit 63 sets the ignition timing at which the ignition plug 16 ignites the air-fuel mixture to be ignition retard control by the vehicle posture control unit 62 so as to reduce the torque for the vehicle posture control (step # 15). That is, when the first condition is satisfied and the second condition is not satisfied, the determination unit 63 retards the drive timing of the ignition plug 16 to reduce the generated torque of the engine body 1. The degree of retardation of the ignition timing is set to be larger as the torque reduction amount is larger. After step # 14 or #15 is executed, the determination unit 63 ends the process (returns to step # 11).
As described above, in the control example of fig. 10A, when the determination unit 63 determines that the first condition and the second condition are satisfied, the generated torque of the engine is reduced not by the ignition delay but by the amount reduction control for reducing the amount of fuel. That is, in the case of spark ignition control compression ignition combustion, the vehicle posture control is executed not by ignition delay but by fuel reduction control. Therefore, the start timing of the SI combustion in the spark ignition control compression ignition combustion is not delayed, so that the heat generated by the SI combustion can sufficiently increase the in-cylinder temperature and pressure, and the CI combustion in the latter half of the combustion can be favorably generated without occurrence of misfire. On the other hand, when the SI combustion is being performed instead of the spark ignition controlled compression ignition combustion, the problem of misfire does not substantially occur. In such a case, the vehicle posture control is executed by the ignition delay, whereby the control can be simplified.
The control example of fig. 10B is an example as follows: the method of engine torque reduction for performing vehicle attitude control is switched depending on whether spark-ignition control compression-ignition combustion is being performed and whether the spark-ignition control compression-ignition combustion is being performed in the first air-fuel ratio mode (λ > 1) performed with a lean air-fuel ratio, that is, depending on whether the engine is operating in the second region A2 of the operation map of fig. 4.
The processing of steps # 21 and #22 is the same as steps # 11 and #12 described above, and therefore, the description thereof is omitted. When the vehicle posture control unit 62 issues a request for additional deceleration (yes in step # 22), the determination unit 63 determines whether the combustion control unit 61 is executing spark-ignition controlled compression-ignition combustion in the first air-fuel ratio mode (λ > 1) (whether the second condition is satisfied and the first air-fuel ratio mode is being executed) (step # 23).
When the spark ignition control compression ignition combustion in the first air-fuel ratio mode is being executed (yes in step # 23), the determination unit 63 sets the vehicle posture control unit 62 to perform a reduction control for reducing the fuel injection amount of the injector 15, thereby reducing the torque used for the vehicle posture control (step # 24). That is, when the first condition and the second condition are satisfied and the first air-fuel ratio mode (λ > 1) is being executed, the determination unit 63 performs the amount reduction control for reducing the amount of fuel supplied into the cylinder 2 in order to reduce the generated torque of the engine body 1.
On the other hand, when the spark-ignition controlled compression-ignition combustion in the first air-fuel ratio mode is not being performed (no in step # 23), that is, when the engine is operating in the SI combustion in the first region A1 or the fourth region A4 of the operation map of fig. 4 or in the spark-ignition controlled compression-ignition combustion in the second air-fuel ratio mode (λ ≦ 1) in the third region A3, the determination unit 63 sets the vehicle attitude control unit 62 to perform ignition retard control for retarding the ignition timing of the mixture to be ignited by the ignition plug 16 so as to reduce the torque for the vehicle attitude control (step # 25). That is, the determination unit 63 retards the drive timing of the ignition plug 16 to reduce the generated torque of the engine main body 1 when the first condition is satisfied and the second condition is not satisfied, and when the first condition and the second condition are satisfied and the second air-fuel ratio mode is being executed.
As described above, in the control example of fig. 10B, when the determination unit 63 determines that the first condition and the second condition are satisfied and determines that the first air-fuel ratio mode (λ > 1) is being executed, the generated torque of the engine is reduced not by the ignition delay but by the amount reduction control for reducing the fuel amount. That is, at the time of compression ignition combustion by spark ignition control of a mixture with a lean air-fuel ratio, vehicle attitude control is executed not by ignition retard but by fuel reduction control. If the ignition delay is performed during combustion in the first air-fuel ratio mode (λ > 1), the mixture becomes lean, so that self-ignition is less likely to occur, and the possibility of misfire is further increased. However, according to the control example described above, since the fuel reduction control is executed in the case where the vehicle attitude control is executed in a situation where the spark ignition control compression ignition combustion in the first air-fuel ratio mode (λ > 1) is executed, it is possible to effectively suppress the misfire.
On the other hand, in contrast to the case where the possibility of misfire is high when the air-fuel ratio of the mixture is lean, in the case where the mixture is set to the second air-fuel ratio mode of the stoichiometric air-fuel ratio or higher, the possibility of misfire is relatively low even if the above-described ignition delay is performed. According to the control example described above, when the vehicle posture control is executed in a situation where the spark ignition control compression ignition combustion in the second air-fuel ratio mode is executed, the torque reduction based on the ignition delay is employed. Therefore, by performing a relatively simple control of the driving timing (ignition timing) of the ignition plug 16, the vehicle posture control can be performed.
[ control for mode switching ]
Next, a process in a case where the vehicle posture control and the mode conversion of the spark ignition control compression ignition combustion are overlapped will be described. In the present embodiment, the spark ignition control compression ignition combustion is performed in the first air-fuel ratio mode (λ > 1) or the second air-fuel ratio mode (λ ≦ 1). For example, the first air-fuel ratio mode is employed as a lean air-fuel ratio for the purpose of improving the thermal efficiency of the engine, and the second air-fuel ratio mode is employed when priority is given to combustion stability or the like. Here, in a state where the mode switching between the first air-fuel ratio mode and the second air-fuel ratio mode of the spark ignition control compression ignition combustion is being executed, there is a possibility that the combustion becomes unstable when the control for reducing the engine torque is intervened in order to execute the vehicle posture control. That is, in a state where the amount of intake air or the amount of fuel injected into the cylinder 2 is changed to switch the air-fuel ratio mode, if the engine torque reduction control is overlapped with this, there is a possibility that the combustion is unstable, and in a serious case, the misfire may occur.
As described above, the air-fuel ratio a/F is set at a lean air-fuel ratio of around 25 to 30/1 (the first air-fuel ratio range) in the case where the spark ignition control compression ignition combustion is performed in the first air-fuel ratio mode, and at air-fuel ratio a/F =14.7/1 (the second air-fuel ratio range) in the case of the second air-fuel ratio mode. Therefore, between the two modes, there is a third air-fuel ratio range that does not belong to either the first air-fuel ratio range or the second air-fuel ratio range. This third air-fuel ratio range is a range in which lean combustion of NOx occurs, and therefore, is avoided. However, when the third air-fuel ratio range exists, a certain time is required because the mode switching between the first and second air-fuel ratio modes, which is accompanied by the change in the intake air amount and the fuel injection amount for adjusting the air-fuel ratio, cannot be performed instantaneously. When the mode switching is performed, the amount of intake air or the amount of fuel injected into the cylinder changes and becomes unstable in order to transit to the air-fuel ratio corresponding to each air-fuel ratio mode. In such a state, when the torque reduction control for controlling the vehicle posture is superimposed thereon, problems such as unstable combustion and occurrence of a misfire occur.
In view of the above, in the present embodiment, the determination unit 63 determines whether or not a situation in which the vehicle posture control and the combustion mode switching of the spark ignition control compression ignition combustion overlap occurs. The determination unit 63 performs control for avoiding the overlap of the both when the overlap occurs. Examples of the overlap avoidance control include the following two controls:
(1) Mode change priority control that suppresses (prohibits) a decrease in torque for vehicle attitude control while mode switching is being performed;
(2) The vehicle attitude control priority control suppresses (prohibits) the mode change even if there is a request for mode switching when the vehicle attitude control is being executed.
Fig. 10C is a flowchart for easily illustrating the mode change priority control in the above-described mode (1). The processing of steps # 31 and #32 is the same as steps # 11 and #12 described in fig. 10A, and therefore description thereof is omitted. After the vehicle posture control section 62 issues the request for additional deceleration (yes in step # 32), the determination section 63 determines whether or not an air-fuel ratio mode switching (switching step) for switching between the first air-fuel ratio mode (λ > 1) and the second air-fuel ratio mode (λ ≦ 1) in the spark ignition control compression ignition combustion is being executed (step # 33).
When the mode switching is being executed (yes in step # 33), the determination unit 63 prohibits the torque reduction control for the vehicle attitude control (suppression step). In this case, the vehicle attitude control unit 62 prioritizes combustion stability without performing vehicle attitude control even in a situation where torque reduction is to be performed (step # 34). On the other hand, when the mode switching is not being performed (no in step # 33), that is, when the spark ignition control compression ignition combustion in the first air-fuel ratio mode or the second air-fuel ratio mode is being performed, or when the SI combustion is being performed, the determination unit 63 does not prohibit the torque reduction control. In this case, the vehicle attitude control unit 62 performs the designated vehicle attitude control in a situation where the torque reduction is to be performed (step # 35).
As described above, in the control example of fig. 10C, when the mode switching between the first air-fuel ratio mode and the second air-fuel ratio mode is being performed, the decrease in the engine torque for the vehicle attitude control is prohibited (suppressed) even if the condition for the vehicle attitude control to be performed arises. Therefore, during the mode switching period in which the intake air amount or the fuel injection amount to the cylinder 2 is changed to become unstable, the overlap of the engine torque reduction control can be suppressed. Therefore, problems such as unstable combustion or occurrence of flame failure in the combustion chamber 6 can be avoided.
Next, fig. 10D is a flowchart simply showing the vehicle attitude control priority control according to the above-described mode (2). After the ECU60 finishes reading the signals of various sensors provided in the vehicle 100 (step # 41), the determination unit 63 determines whether or not there is a mode switching request to switch the air-fuel ratio mode between the first air-fuel ratio mode (λ > 1) and the second air-fuel ratio mode (λ ≦ 1) (switching determination step; step # 42). That is, even when the spark ignition control compression ignition combustion in either the first air-fuel ratio mode or the second air-fuel ratio mode is currently being performed, the determination unit 63 determines whether or not the combustion control unit 61 is in a situation where the air-fuel ratio mode should be switched. When there is no request for switching the air-fuel ratio mode (no in step # 42), the determination unit 63 ends the process (returns to step # 41).
When there is a request for switching the air-fuel ratio mode (yes in step # 42), the determination unit 63 then determines whether the vehicle posture control unit 62 issues a request for additional deceleration (torque reduction), that is, whether vehicle posture control is being executed (step # 43). When the vehicle attitude control by the vehicle attitude control unit 62 is being performed (the first condition is satisfied) (yes in step # 43), the determination unit 63 prohibits the switching of the air-fuel ratio mode (suppressing step; step # 44). On the other hand, when the vehicle posture control unit 62 is not executing the vehicle posture control (no in step # 43), the determination unit 63 permits the switching of the air-fuel ratio mode, and the combustion control unit 61 performs the required mode switching (step # 45).
As described above, in the control example of fig. 10D, if the vehicle attitude control is being executed, even if there is a request for switching the air-fuel ratio mode between the first air-fuel ratio mode and the second air-fuel ratio mode, the execution of the mode switching is suppressed (prohibited). At the time of switching the air-fuel ratio mode, the amount of intake air or the amount of fuel injected into the cylinder 2 changes to make the state unstable in order to transit to the air-fuel ratio corresponding to each air-fuel ratio mode. However, according to the above-described embodiment, in a state where the vehicle posture control is being executed, the formation of such an unstable state can be suppressed. Therefore, problems such as unstable combustion or occurrence of flame failure in the combustion chamber 6 can be avoided.
[ specific examples of control methods for Engine ]
Next, a specific embodiment of operation control to which the engine control method according to the present invention is applied will be described. Fig. 11 is a flowchart showing basic operations of the engine control method according to the present embodiment. After the process is started, ECU60 (fig. 3) reads sensor signals relating to the operating state of vehicle 100 output from various sensors SN1 to SN13 (step S1). Next, ECU60 (vehicle attitude control unit 62) refers to the vehicle speed (crank angle sensor SN 1), the accelerator opening (accelerator opening sensor SN 10), the steering angle (steering angle sensor SN 11), the shift range currently set in the transmission of vehicle 100, and the like obtained based on the sensor signal read in step S1, and performs a process of setting an additional deceleration (torque reduction amount) for vehicle attitude control (step S2; torque reduction setting step). A specific example of the additional deceleration setting process is the example described above with reference to the flowchart of fig. 8. Next, the ECU60 executes the engine control process in consideration of the additional deceleration set in step S2 (step S3). The engine control process of step S3 will be described in detail below with reference to the flowcharts shown in fig. 12 to 15.
< setting of control target value of combustion operation >
Fig. 12 is a flowchart showing details of the engine control process, and mainly shows a procedure of setting a control target value of the combustion operation. After the control process is started, ECU60 (combustion control unit 61) sets a target acceleration (target G) of vehicle 100 with reference to the vehicle speed and the accelerator position obtained in step S1 of fig. 11, the current transmission shift position, and the like (step S11). Next, the ECU60 sets a target basic engine torque for achieving the set target acceleration (step S12). The target base engine torque is a required torque calculated from the amount of depression of the accelerator 107 by the driver before considering the torque reduction by the vehicle attitude control.
Subsequently, ECU60 sets a target combustion mode based on the target basic engine torque and the engine speed detected by crank angle sensor SN1 (step S13; combustion mode setting step). In setting the target combustion mode, for example, an operation map shown in fig. 4, which is predetermined based on the relationship between the engine speed and the load, is referred to. That is, the ECU60 determines whether or not the current engine speed and the target basic engine torque (load) set in step S12 belong to any of the first to fourth regions A1 to A4 of the operation map, and sets the combustion mode shown in any of the graphs (a) to (e) of fig. 5 as the target combustion mode.
Then, ECU60 (determination unit 63) sets the execution method of torque reduction in vehicle attitude control based on the target combustion mode set in step S13 (step S14). As described above, in the present embodiment, as a method of executing the torque reduction, either the fuel injection amount injected from the injector 15 is decreased or the ignition delay that retards the drive timing of the ignition plug 16 is adopted. A control example of whether any of the above is selected is the one shown in the flowcharts of fig. 10A and 10B before. For example, in the case of the control example shown in fig. 10B, the relationship between the target combustion mode and the method of executing the torque reduction is shown in table 1 below.
TABLE 1
Next, ECU60 (determination unit 63) determines whether or not there is a request for switching between the first air-fuel ratio mode (λ > 1) and the second air-fuel ratio mode (λ = 1) in the spark-ignition controlled compression-ignition combustion (switching determination step; step S15). Further, the switching determination between the first air-fuel ratio mode (λ > 1) and the second air-fuel ratio mode (λ = 1) is performed in accordance with the target base engine torque set in step S12 before the torque reduction amount based on the vehicle posture control is subtracted.
The determination step in step S15 corresponds to the step of executing the overlap avoidance control described above with reference to fig. 10C and 10D. Here, an example in which the "mode change priority control" described with reference to fig. 10C is applied is shown. When the mode switching request is not made (yes in step S15), the determination unit 63 executes the torque reduction control for the vehicle attitude control (steps S16 to S18 described below), and when the mode switching request is made (no in step S15), the torque reduction control for the vehicle attitude control is prohibited (suppressing step). In the latter case, torque mode switching control (control shown in fig. 14 or fig. 15 to be described later) is executed to perform the mode switching and the like without torque fluctuation.
If there is no request for switching the mode (yes in step S15), ECU60 (combustion control unit 61) sets a target final engine torque based on the target basic engine torque set in step S12 and the torque reduction amount set in step S2 (step # 9 in fig. 8) in fig. 11 (step S16). The target final engine torque is a torque obtained by subtracting a torque reduction amount by the vehicle attitude control from the required torque. Of course, in the case where there is no request for execution of the vehicle attitude control, the torque reduction amount to be subtracted is zero. Then, the ECU60 sets a target combustion pressure in the combustion chamber 6 based on the target final engine torque (step S17).
Then, ECU60 sets a control target value for the combustion operation based on the target combustion pressure set in step S17 and the target combustion pattern set in step S13 (step S18). Specifically, a target air amount supplied to the combustion chamber 6, a target auto-ignition timing at which CI combustion is exhibited, a target SI rate, a target air-fuel ratio, a target ignition timing of the mixture by the ignition plug 16, and the like are set.
The SI rate is a ratio of a total heat release amount by spark ignition control compression ignition combustion to a heat release amount by SI combustion. Referring to fig. 6, an inflection point X in the figure is a timing at which the combustion state is switched from SI combustion to CI combustion. An area R1 of the waveform of the heat generation rate located on the advance angle side with respect to the crank angle θ CI corresponding to the inflection point X is the heat generation amount by the SI combustion, and an area R2 of the waveform of the heat generation rate located on the retard angle side with respect to θ CI is the heat generation rate by the CI combustion. The SI rate can be expressed by SI rate = R1/(R1 + R2) using the areas R1 and R2.
Fig. 16 is a table diagram showing the relationship between the target combustion pattern, the total fuel injection amount, and the ignition timing in the case where the control example shown in fig. 10B is employed for setting the method of executing the torque reduction in step S14. In the case of "no torque reduction" for vehicle attitude control, the first air-fuel ratio mode 71A (λ > 1) of spark ignition control compression ignition combustion, the second air-fuel ratio mode 72A (λ = 1) of SPCCI combustion, and the SI combustion mode 73A are set to the specified total fuel injection amounts f1, f2, and f3, respectively, and the ignition timing is also set to the specified crank angle CA1.
On the other hand, in the case of "torque reduction" for vehicle attitude control, in the first air-fuel ratio pattern 71B (λ > 1) of spark ignition control compression ignition combustion, the total fuel injection amount is changed to f4 which is decreased by a specified amount from f1 in the case of "no torque reduction". On the other hand, the target ignition timing is maintained at the timing of the crank angle CA1 without performing ignition retard. In the second air-fuel ratio pattern 72B (λ = 1) of the spark-ignition controlled compression-ignition combustion, in the case of "torque down", the total fuel injection amount is maintained at f2 while the ignition retard is performed to retard the target ignition timing from the crank angle CA1 to CA 2. Similarly, in the SI combustion mode 73B, in the case of "torque down", the total fuel injection amount is maintained at f3 while the ignition delay is performed to retard the target ignition timing from the crank angle CA1 to CA 2.
< details of spark ignition control compression ignition combustion control >
Fig. 13 is a flowchart showing details of the engine control process, and mainly shows steps related to detailed control of spark ignition controlled compression ignition combustion. Subsequent to step S18 in fig. 12, ECU60 determines whether or not the above-described SI rate is less than 100%, that is, whether or not the target combustion mode is spark-ignition controlled compression-ignition combustion (SI rate =100% means SI combustion) (step S20).
When the target combustion mode is the spark-ignition controlled compression-ignition combustion (second combustion mode) (yes in step S20), first, a process of setting control values of actuators other than the injector 15 and the ignition plug 16 is performed (steps S21 to S24). Specifically, the ECU60 (combustion control unit 61) sets the target EGR rate based on the target air amount set in step S18 and the estimated in-cylinder temperature at the target self-ignition timing (step S21). In the present embodiment, the following are executed as EGR: internal EGR that is executed based on the opening/closing timing operation (early opening of the intake valve 11 or late closing of the exhaust valve 12) of the intake valve 11 and the exhaust valve 12 (see fig. 2); the external EGR recirculates the exhaust gas through the EGR passage 51. Thus, the target internal EGR rate and the target external EGR rate are set in step S21. Then, a target intake valve opening/closing timing as an opening/closing timing of the intake valve 11, a target exhaust valve opening/closing timing as an opening/closing timing of the exhaust valve 12 for achieving the target internal EGR rate, and a target EGR valve opening degree as an opening degree of the EGR valve 53 for achieving the target external EGR rate are set (step S22).
Next, the ECU60 sets a target throttle opening degree as the opening degree of the throttle valve 32, a target bypass valve opening degree as the opening degree of the bypass valve 39 of the bypass passage 38, and a target clutch engagement degree as the engagement degree of the electromagnetic clutch 34 of the supercharger 33 for achieving the target air amount (step S23). Then, the ECU60 sends an operation command to the actuators provided in the respective control targets so as to achieve the respective targets of the target throttle valve opening degree, the target intake valve opening and closing timing, the target exhaust valve opening and closing timing, the target bypass valve opening degree, the target EGR valve opening degree, and the target clutch engagement degree described above (step S24). That is, each actuator is operated based on the target value for achieving the spark-ignition controlled compression-ignition combustion set in step S18.
Next, correction processing for correcting the combustion injection amount and injection timing of the injector 15 and the ignition timing of the ignition plug 16 is executed based on the actual combustion reactivity with respect to the target value (steps S25 to S29). A valve driven by an actuator or the like is a reaction-less favorable device that is difficult to operate immediately to a target value. The operation delay of these devices may affect, for example, the achievement of the target air-fuel ratio. The ECU60 grasps the degree of deviation of the actual combustion state from the target combustion state due to the operation delay, and corrects the combustion injection amount and the injection timing of the injector 15 having excellent reactivity and the ignition timing of the ignition plug 16 having excellent reactivity according to the state of the internal gas actually formed in the combustion chamber 6 in order to correct the deviation.
Specifically, the ECU60 calculates the in-cylinder temperature, the intake air filling amount, and the in-cylinder oxygen concentration of the cylinder 2 at the actual intake valve closing timing (step S25). At the time of this calculation, reference is made to: an actual state quantity of intake gas obtained from the detection value of the air flow sensor SN4, the first and second intake temperature sensors SN5 and SN7, the external EGR rate, and the like; the actual state quantity of the internal gas in the cylinder 2, which is obtained from the detection values of the intake cam angle sensor SN12 and the exhaust cam angle sensor SN13, and the like; the last combustion result. As the previous combustion result, the auto-ignition timing obtained from the waveform of the actual in-cylinder pressure derived from the detection value of the in-cylinder pressure sensor SN3, or the like is used.
Next, ECU60 sets a target combustion injection amount and a target injection timing of injector 15 so as to be the target air-fuel ratio set in step S18, based on the intake air charge amount and the in-cylinder oxygen concentration determined in step S25 (step S26). As illustrated in fig. 5 (a) and (b), fuel injection is performed in two times in the first air-fuel ratio mode (λ > 1) and the second air-fuel ratio mode (λ = 1) of spark-ignition controlled compression-ignition combustion. Therefore, the ECU60 determines the injection amount and the injection timing of the first and second combustion injections so as to achieve the target air-fuel ratio. Then, the ECU60 sends a command to the injector 15 to achieve the target combustion injection amount and the target injection timing (step S27).
Next, the ECU60 sets the target ignition timing of the ignition plug 16 based on the in-cylinder temperature of the cylinder 2 at the actual intake valve closing timing (step S28). The target ignition timing is corrected so that the target ignition timing set in step S18 starts CI combustion, similarly to the target ignition timing set in step S18. Then, the ECU60 drives the ignition plug 16 so as to ignite the air-fuel mixture at the corrected target ignition timing (step S29).
On the other hand, if it is determined in step S20 that the SI rate is not less than 100%, that is, if the target combustion mode is SI combustion (first combustion mode) (no in step S20), the ECU60 sets the target throttle valve opening degree, the target intake valve opening/closing timing, the target exhaust valve opening/closing timing, the target bypass valve opening degree, the target clutch engagement degree, the target EGR valve opening degree, and the like, based on the target air amount set in step S18 (step S30). Next, the ECU60 sets a target fuel injection amount and a target injection timing for the injector 15 and a target ignition timing for the ignition plug 16 based on the target air amount and the target combustion pressure set in step S18 in the same manner (step S31). Then, the ECU60 drives the actuators, the injector 15, and the ignition plug 16 so as to achieve the above-described target values (step S32).
< mode switching control switching from λ =1 to lean >
Next, the torque mode switching control (air-fuel ratio mode setting step) executed when there is a mode switching request between the first air-fuel ratio mode (λ > 1) and the second air-fuel ratio mode (λ = 1) of the spark ignition control compression ignition combustion in step S15 will be described. Fig. 14 is a flowchart showing mode switching control in the case where a mode switching request is made from the second air-fuel ratio mode to the first air-fuel ratio mode, and fig. 17 is a time chart showing the relationship between the mode switching and the intake air amount, the fuel amount, the ignition timing, the engine torque, and the air-fuel ratio.
If there is a mode switching request in step S15 shown in fig. 12 (no in step S15), the process proceeds to step S41 in fig. 14. In the case where there is a torque reduction request for vehicle attitude control at this stage, the torque reduction is prohibited and mode switching is prioritized. ECU60 (determination unit 63) determines whether or not the mode switching request is a mode switching request for switching from the second air-fuel ratio mode to the first air-fuel ratio mode, that is, whether or not the mode switching request is a mode switching request for changing the spark-ignition controlled compression-ignition combustion from λ =1 to a lean air-fuel ratio (step S41). When a mode switching request is made from the second air-fuel ratio mode to the first air-fuel ratio mode (yes in step S41), the determination unit 63 instructs the combustion control unit 61 to perform control for making the air-fuel ratio a/F transition from λ =1 to a lean air-fuel ratio and maintaining the engine torque during the mode switching at a predetermined value without deteriorating the emission.
Specifically, the ECU60 (combustion control unit 61) adjusts the opening degree of the throttle valve 32 to increase the intake air amount (step S42), and increases the fuel injection amount of the injector 15 (step S43). Referring to fig. 17, time T0 to T1 is an execution period of the second air-fuel ratio mode, and time T1 to T2 is a mode switching period from the second air-fuel ratio mode to the first air-fuel ratio mode. ECU60 increases the intake air amount and the fuel amount at times T0 to T1 at which the first air-fuel ratio mode (λ > 1) is achieved in proportion to the graph during times T1 to T2 (intake air amount increasing step and fuel increasing step). The reason why the intake air amount is gradually increased to point to lean and the fuel amount is also gradually increased during this period is to avoid the formation of an air-fuel ratio state in which NOx occurs.
In parallel with the above, the ECU60 retards the ignition timing of the ignition plug 16 during the time T1 to T2 (step S44). This is to suppress the engine torque from also varying to the increase side due to the increase in the fuel amount during the time T1 to T2 (first delay step). The delay of the ignition timing is performed so that the ignition timing is gradually switched to the delay side as the fuel amount gradually increases. Since the engine torque is reduced based on such an ignition delay, the increase in the fuel amount can be cancelled out, and the constant torque can be maintained during the time T1 to T2.
In the present embodiment, the air-fuel ratio a/F =25/1 is a rich limit at which no NOx is generated during lean combustion in the first air-fuel ratio mode, and the air-fuel ratio a/F =30/1 is a specified air-fuel ratio in the first air-fuel ratio mode, and therefore, it is determined in step S45 whether the air-fuel ratio =25 has been reached, and if not (no in step S45), steps S42 to S44 are repeated, that is, the intake air amount and the fuel amount are further increased, and the ignition timing is further delayed.
On the other hand, when the intake air amount that enables the air-fuel ratio =25 is reached (yes in step S45), ECU60 rapidly decreases the fuel amount to an amount necessary to form a lean mixture of the first air-fuel ratio mode (step S46). Time T2 in the time chart of fig. 17 is the time of this rapid decrease. As a result, a first air-fuel ratio pattern (λ > 1) is formed in the combustion chamber 6, and an air-fuel mixture having an air-fuel ratio at which no NOx occurs is formed. At this point, since the torque reduction operation is not required, ECU60 ends the ignition retard (step S47). Further, the intake air amount is also increased after the elapse of time T2. That is, the intake air amount is increased to the time T2A when the intake air amount that can form the specified air-fuel ratio =30 is reached.
< switching of mode switching control from lean to λ =1 >
Next, referring to fig. 15 and 17, the torque mode switching control executed when a switching request is made from the first air-fuel ratio mode (λ > 1) to the second air-fuel ratio mode (λ = 1) will be described. Fig. 15 is a flowchart showing mode switching control when a mode switching request is made from the first air-fuel ratio mode to the second air-fuel ratio mode.
In step S41 in fig. 14, if a mode switching request from the second air-fuel ratio mode to the first air-fuel ratio mode is not made (no in step S41), the process proceeds to step S51 in fig. 15. In this case, the determination unit 63 of the ECU60 gives an instruction to the combustion control unit 61 to execute the following control: the air-fuel ratio A/F is switched from lean to lambda =1 without deteriorating the emission, and the engine torque during the mode switching is maintained at a predetermined value.
Specifically, the ECU60 (combustion control unit 61) adjusts the opening degree of the throttle valve 32 so as to decrease the intake air amount (intake air amount decreasing process; step S51). On the other hand, the fuel injection amount of the injector 15 is maintained (step S52). Referring to fig. 17, time T2 to T3 is a period during which the first air-fuel ratio mode is executed, and time T3 to T5 is a period during which the mode is switched from the first air-fuel ratio mode to the second air-fuel ratio mode. The ECU60 decreases the intake air amount at times T2A to T3 when the first air-fuel ratio mode (λ > 1) is achieved as shown in the graph during times T3 to T4. On the other hand, the fuel injection amount during the times T3 to T4 is the same as that of the times T2A to T3.
Next, the ECU60 confirms whether the intake air amount reaches a specified amount-reduced intake air amount (air-fuel ratio) (step S53). The amount-reduced intake air amount is an intake air amount that achieves an air-fuel ratio a/F =25/1 as a rich limit in which no NOx is generated in the lean combustion in the first air-fuel ratio mode. If the air-fuel ratio =25 is not achieved (no in step S53), the process returns to step S51, and the intake air amount is further decreased.
On the other hand, when time T4 at which the air-fuel ratio =25 is reached (yes in step S53), control for preventing generation of NOx is executed. Specifically, ECU60 continues to decrease the intake air amount (step S54), and sharply increases the fuel injection amount of injector 15 so that an air-fuel mixture of air-fuel ratio =14.7 (λ = 1) is formed from the intake air amount at time T4 (step S55). In order to maintain λ =1, the fuel injection amount is decreased in accordance with the decrease in the intake air amount after time T4. This can avoid the formation of an air-fuel ratio state in which NOx is generated. Further, in order to cancel the increase in the engine torque due to the increase in the fuel amount, the ECU60 abruptly retards the ignition timing of the ignition plug 16 in accordance with the intake air amount and the fuel injection amount at the time T4, in the same manner as in step S44 described above (a second retarding step) (step S56). This can prevent torque fluctuation around time T4.
ECU60 confirms whether or not the intake air amount reaches the target value of the intake air amount set for the second air-fuel ratio mode (λ = 1) (step S57). That is, the air-fuel ratio is decreased to the air-fuel ratio =14.7 at the time T4, but it is confirmed whether the intake air amount has decreased to an amount that enables the second air-fuel ratio mode to be executed. If not (no in step S57), steps S54 to S56 are repeated. That is, the intake air amount and the fuel amount are further reduced, while the delay of the ignition timing is gradually reduced. This enables the constant torque to be maintained during the time period T4 to T5.
On the other hand, when the intake air amount for the second air-fuel ratio mode (λ = 1) is reached (yes in step S57), ECU60 stops further reduction of the intake air amount and the fuel injection amount (step S58). The time T5 in the time chart of fig. 17 is the time of the stop. As a result, an air-fuel mixture of λ =1 satisfying the intake air amount for the second air-fuel ratio mode is formed in the combustion chamber 6. Then, ECU60 ends the ignition retard at time T5 (step S59). Further, immediately before the time T5, the torque reduction due to the ignition delay is naturally extremely small. After step S47 of fig. 14 or step S59 of fig. 15 described above is completed, the process returns to "return" in fig. 13, that is, to step S11 of fig. 12, and the same process is repeated.
[ modified examples ]
The embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and the following modified embodiments may be adopted.
(1) In the above embodiment, the vehicle 100 configured by the FF drive vehicle is exemplified as an example of the vehicle. The engine control method and the engine system according to the present invention may also be applied to FR drive vehicles, four-wheel drive vehicles, and hybrid vehicles having a motor and an engine driven by electric power supplied from a battery or a capacitor as drive sources.
(2) In the above-described embodiment, an example is shown in which the torque reduction for the vehicle attitude control is completely prohibited when the air-fuel ratio mode switching between the first air-fuel ratio mode (λ > 1) and the second air-fuel ratio mode (λ = 1) is being performed. Instead of this, the following control may be adopted: the torque reduction is inhibited from being partially reduced in the torque reduction amount necessary for the vehicle attitude control, so that the reduction of the generated torque of the engine is suppressed.
(3) In the priority control of the vehicle posture control shown in fig. 10D, an example is shown in which the mode switching between the first air-fuel ratio mode and the second air-fuel ratio mode is prohibited in a state in which the vehicle posture control is being executed (step # 44). Instead of prohibiting switching of the air-fuel ratio mode, the above-described suppression control may be adopted in which the switching of the air-fuel ratio mode is delayed to, for example, a time after completion of the vehicle posture control or between the vehicle posture controls.
(4) The time chart of fig. 17 shows an example of "equal torque" for maintaining the engine torque at a predetermined value during the mode switching period (time T1 to time T2 and time T3 to time T5 of fig. 17). The "constant torque" does not mean a state that is not allowed even if there is a slight torque variation, and the torque variation may occur within a range where the torque is actually regarded as a predetermined value.
(5) In the above-described embodiment, an example is described in which the torque reduction for the vehicle posture control is completely switched to the fuel reduction control instead of the ignition delay at the time of the spark ignition control compression ignition combustion (the example of fig. 10A) or the time of the spark ignition control compression ignition combustion in the first air-fuel ratio mode (the examples of fig. 10B and fig. 12 to 15). Instead of this, a part of the torque required for the vehicle attitude control may be reduced by the ignition delay (control for suppressing the degree of the ignition delay) and the remaining part may be reduced by the fuel amount reduction control.
[ inventions contained in the above-described embodiments ]
The above-described embodiments mainly include the inventions having the following technical means.
A method of controlling an engine according to an aspect of the present invention is a method of controlling an engine that is mounted on a vehicle having steered wheels, is mechanically coupled to drive wheels of the vehicle, and is provided with an ignition plug, the method including: a combustion mode setting step of selecting a combustion mode of the engine between a first combustion mode in which all of an air-fuel mixture in a cylinder of the engine is combusted based on propagation of a flame generated by the ignition plug and a second combustion mode in which at least a part of the air-fuel mixture in the cylinder is combusted based on self-ignition, in accordance with an operation state of the engine; an air-fuel ratio mode setting step of, when the second combustion mode is selected in the combustion mode setting step, selecting an air-fuel ratio mode between a first air-fuel ratio mode and a second air-fuel ratio mode in accordance with an operating state of the engine, the first air-fuel ratio mode being a mode in which the air-fuel mixture is leaner than a stoichiometric air-fuel ratio, the second air-fuel ratio mode being a mode in which the air-fuel mixture is equal to or richer than the stoichiometric air-fuel ratio; a switching step of switching an air-fuel ratio mode according to the air-fuel ratio mode selected in the air-fuel ratio mode setting step; a reduced torque setting step of setting a torque reduction amount for reducing the torque generated by the engine, based on a steering angle of the steering wheel; and a suppressing step of suppressing a decrease in the generated torque of the engine based on the torque decrease amount set in the decrease torque setting step when the air-fuel ratio mode is being switched in the switching step.
Further, an aspect of the present invention relates to an engine system including: an engine mounted on a vehicle having a steering wheel, mechanically coupled to a drive wheel of the vehicle, and including a spark plug; an operating state sensor that detects an operating state of the engine; a steering angle sensor that detects a steering angle of the steering wheel; and a controller; wherein the controller selects a combustion mode of the engine between a first combustion mode and a second combustion mode in accordance with a detection result of the operating condition sensor, the first combustion mode being a mode in which all of the air-fuel mixture in a cylinder of the engine is combusted based on propagation of a flame generated by the ignition plug, the second combustion mode being a mode in which at least a part of the air-fuel mixture in the cylinder is combusted based on self-ignition, the controller selects an air-fuel ratio mode between a first air-fuel ratio mode and a second air-fuel ratio mode in accordance with the operating condition of the engine when the second combustion mode is selected as the combustion mode of the engine, the first air-fuel ratio mode being a mode in which the air-fuel mixture is leaner than a stoichiometric air-fuel ratio, the second air-fuel ratio mode being a mode in which the air-fuel mixture is equal to or richer than the stoichiometric air-fuel ratio, the controller performs switching of the air-fuel ratio modes in accordance with the selected air-fuel ratio mode, the controller sets a torque reduction amount for reducing the torque of the engine in accordance with the detection result of the steering angle sensor, and the controller performs the switching of the control based on the reduced torque setting of the reduced torque.
According to the engine control method or the engine system described above, the torque reduction amount is set based on the steering angle of the steering wheel. This corresponds to performing vehicle attitude control. Further, the first combustion mode corresponds to SI combustion, and the second combustion mode corresponds to spark ignition controlled compression ignition combustion. Further, when the air-fuel ratio mode is switched between the first air-fuel ratio mode and the second air-fuel ratio mode during combustion of the air-fuel mixture in the cylinder, a decrease in the generated torque of the engine based on the torque decrease amount set in the decrease torque setting step is suppressed.
That is, when the air-fuel ratio mode is being switched, even if a condition for executing the vehicle attitude control occurs, a decrease in the engine torque for the vehicle attitude control is suppressed. When the air-fuel ratio mode is switched, the amount of intake air or the amount of fuel injected into the cylinder changes and becomes unstable in order to transit to the air-fuel ratio corresponding to each mode. However, according to the above-described configuration, in the unstable state as described above, since the overlap of the engine torque reduction control is suppressed, it is possible to avoid the problems such as unstable combustion and occurrence of a misfire.
A method for controlling an engine according to another aspect of the present invention is a method for controlling an engine that is mounted on a vehicle having steered wheels, mechanically coupled to drive wheels of the vehicle, and provided with an ignition plug, the method including: a combustion mode setting step of selecting a combustion mode of the engine between a first combustion mode in which all of an air-fuel mixture in a cylinder of the engine is combusted by propagation of a flame generated by the ignition plug and a second combustion mode in which at least a part of the air-fuel mixture in the cylinder is combusted by self-ignition, in accordance with an operation state of the engine; an air-fuel ratio mode setting step of, when the second combustion mode is selected in the combustion mode setting step, selecting an air-fuel ratio mode between a first air-fuel ratio mode and a second air-fuel ratio mode in accordance with an operating state of the engine, the first air-fuel ratio mode being a mode in which the air-fuel mixture is leaner than a stoichiometric air-fuel ratio, the second air-fuel ratio mode being a mode in which the air-fuel mixture is equal to or richer than the stoichiometric air-fuel ratio; a switching determination step of determining whether or not there is an air-fuel ratio mode switching request based on the air-fuel ratio mode selected in the air-fuel ratio mode setting step; a reduced torque setting step of setting a torque reduction amount for reducing the torque generated by the engine, based on a steering angle of the steering wheel; and a suppressing step of suppressing switching of the air-fuel ratio mode based on the switching request when it is determined in the switching determining step that the switching request of the air-fuel ratio mode is made when the torque reduction amount is set in the reduced torque setting step.
Further, another aspect of the invention relates to an engine system including: an engine mounted on a vehicle having a steering wheel, mechanically coupled to a drive wheel of the vehicle, and including a spark plug; an operating state sensor that detects an operating state of the engine; a steering angle sensor that detects a steering angle of the steering wheel; and a controller; wherein the controller selects a combustion mode of the engine between a first combustion mode and a second combustion mode in accordance with a detection result of the operating condition sensor, the first combustion mode being a mode in which all of the air-fuel mixture in a cylinder of the engine is combusted based on propagation of a flame generated by the ignition plug, the second combustion mode being a mode in which at least a part of the air-fuel mixture in the cylinder is combusted based on self-ignition, the controller selects an air-fuel ratio mode between a first air-fuel ratio mode and a second air-fuel ratio mode in accordance with the operating condition of the engine when the second combustion mode is selected as the combustion mode of the engine, the first air-fuel ratio mode being a mode in which the air-fuel mixture is leaner than a stoichiometric air-fuel ratio, the second air-fuel ratio mode being a mode in which the air-fuel mixture is equal to or richer than the stoichiometric air-fuel ratio, the controller determines whether an air-fuel ratio mode switching request based on the selected air-fuel ratio mode is present, the controller sets an amount of torque generation of the engine to be decreased based on the detection result of the steering angle sensor, and the controller determines that the switching request is based on the switching request, and the controller determines that the switching request is based on the switching request.
In the above-described engine control method or engine system, when it is determined that a mode switching request is made between the first air-fuel ratio mode and the second air-fuel ratio mode in a state where the torque reduction amount is set in the reduced torque setting step, switching of the air-fuel ratio mode is suppressed. That is, in a state where the vehicle attitude control is being executed, even if there is a request for switching the air-fuel ratio mode, the execution of the mode switching is suppressed. When the air-fuel ratio mode is switched, the intake air amount or the fuel injection amount into the cylinder changes to make the transition to the air-fuel ratio suitable for each mode unstable. However, according to the above-described aspect, since the formation of the unstable state as described above is suppressed while the vehicle attitude control is being executed, it is possible to avoid problems such as unstable combustion or occurrence of a misfire.
In the above method of controlling an engine, it is preferable that the engine includes a fuel injection valve, and the method further includes: an intake air amount increasing step of increasing an amount of intake air into the cylinder during switching from the second air-fuel ratio mode to the first air-fuel ratio mode; a fuel increase step of controlling the fuel injection valve to increase the amount of fuel supplied into the cylinder in accordance with an increase in the intake air amount; and a first retarding step of retarding an ignition timing of the ignition plug so that a torque generated by the engine becomes equal to an equal torque in accordance with an increase in the intake air amount increasing step.
According to this engine control method, the fuel amount is increased in accordance with an increase in the intake air amount in switching from the second air-fuel ratio mode to the first air-fuel ratio mode. Therefore, the generation of NOx can be suppressed. In the air-fuel ratio mode switching, the ignition timing of the spark plug is retarded by a first retarding step in order to suppress torque fluctuations associated with increases in the intake air amount and the fuel amount. Therefore, the operating performance at the time of switching the air-fuel ratio mode can be stabilized.
In the above engine control method, it is preferable that the method further includes: an intake air amount reducing step of reducing an amount of intake air into the cylinder in switching from the first air-fuel ratio mode to the second air-fuel ratio mode; and a second retarding step of retarding an ignition timing of the ignition plug so that a torque generated by the engine becomes equal to a torque corresponding to a decrease in the intake air amount decreasing step.
According to this engine control method, since torque variation during switching of the air-fuel ratio mode is suppressed by the second delay step, the operating performance at the time of switching of the air-fuel ratio mode can be stabilized.
In the above-described engine control method, it is preferable that the torque generated by the engine is reduced by retarding the ignition timing of the spark plug. According to this engine control method, the vehicle attitude control can be executed by a relatively simple control of retarding the ignition timing of the ignition plug.
In the above-described engine control method, it is preferable that the suppressing in the suppressing step is to prohibit a decrease in the generated torque of the engine. Thus, even if a condition for executing the vehicle posture control occurs while the air-fuel ratio mode is being switched, the overlap of the engine torque reduction control for the vehicle posture control is prohibited. Therefore, the instability of combustion can be reliably prevented.
In the above-described engine control method, the suppressing in the suppressing step is preferably to prohibit switching of the air-fuel ratio mode. Thus, in a state where the vehicle posture control is being executed, even if there is a request for switching the air-fuel ratio mode, the execution of the mode switching is prohibited. Therefore, the instability of combustion can be reliably prevented.
In the above-described engine control method, it is assumed that an air-fuel ratio range that does not belong to either the first air-fuel ratio range and the second air-fuel ratio range exists between the first air-fuel ratio range and the second air-fuel ratio range of the mixture, the first air-fuel ratio range being the air-fuel ratio range of the mixture formed in the first air-fuel ratio mode, and the second air-fuel ratio range being the air-fuel ratio range of the mixture formed in the second air-fuel ratio mode.
If there is an air-fuel ratio range that does not belong to any of the air-fuel ratio modes between the air-fuel ratio ranges of the first and second air-fuel ratio modes, switching of the air-fuel ratio mode with changing the intake air amount and the fuel amount cannot be performed instantaneously, and a certain time is required. Therefore, if the engine torque reduction control for vehicle attitude control is superimposed at the time of switching the air-fuel ratio mode, the combustion is likely to become unstable. Therefore, under the above-mentioned premise, the above-mentioned technical solutions of the present invention have particular utility.
According to the present invention described above, it is possible to provide a control method of an engine capable of suppressing unstable combustion in an engine in which compression ignition combustion and vehicle posture control are controlled by spark ignition in combination, the compression ignition combustion being controlled by spark ignition in which combustion is switched between λ >1 and λ ≦ 1 in accordance with the air-fuel ratio mode of the air-fuel mixture, and an engine system to which the control method is applied.
Claims (9)
1. A method of controlling an engine that is mounted on a vehicle having steered wheels, that is mechanically coupled to drive wheels of the vehicle, and that is provided with a spark plug, the method comprising:
a combustion mode setting step of selecting a combustion mode of the engine between a first combustion mode in which all of an air-fuel mixture in a cylinder of the engine is combusted based on propagation of a flame generated by the ignition plug and a second combustion mode in which at least a part of the air-fuel mixture in the cylinder is combusted based on self-ignition, in accordance with an operation state of the engine;
an air-fuel ratio mode setting step of, when the second combustion mode is selected in the combustion mode setting step, selecting an air-fuel ratio mode between a first air-fuel ratio mode and a second air-fuel ratio mode in accordance with an operating state of the engine, the first air-fuel ratio mode being a mode in which the air-fuel mixture is leaner than a stoichiometric air-fuel ratio, the second air-fuel ratio mode being a mode in which the air-fuel mixture is equal to or richer than the stoichiometric air-fuel ratio;
a switching step of switching an air-fuel ratio mode according to the air-fuel ratio mode selected in the air-fuel ratio mode setting step;
a reduced torque setting step of setting a torque reduction amount for reducing the torque generated by the engine, based on a steering angle of the steering wheel; and
a suppressing step of suppressing a decrease in the generated torque of the engine based on the torque decrease amount set in the decrease torque setting step when the air-fuel ratio mode is being switched in the switching step;
the engine is provided with a fuel injection valve,
the control method of the engine further includes:
an intake air amount increasing step of increasing an amount of intake air into the cylinder during switching from the second air-fuel ratio mode to the first air-fuel ratio mode;
a fuel increase step of controlling the fuel injection valve to increase the amount of fuel supplied into the cylinder in accordance with an increase in the intake air amount; and
a first retarding step of retarding an ignition timing of the ignition plug so that a torque generated by the engine becomes equal in response to an increase in the intake air amount.
2. The control method of an engine according to claim 1, characterized in that:
the suppression in the suppression step is to prohibit a decrease in the generated torque of the engine.
3. A method of controlling an engine that is mounted on a vehicle having steered wheels, that is mechanically coupled to drive wheels of the vehicle, and that is provided with a spark plug, the method comprising:
a combustion mode setting step of selecting a combustion mode of the engine between a first combustion mode in which all of an air-fuel mixture in a cylinder of the engine is combusted by propagation of a flame generated by the ignition plug and a second combustion mode in which at least a part of the air-fuel mixture in the cylinder is combusted by self-ignition, in accordance with an operation state of the engine;
an air-fuel ratio mode setting step of selecting an air-fuel ratio mode between a first air-fuel ratio mode in which the air-fuel mixture is leaner than a theoretical air-fuel ratio and a second air-fuel ratio mode in which the air-fuel mixture is equal to or richer than the theoretical air-fuel ratio, depending on an operating state of the engine, when the second combustion mode is selected in the combustion mode setting step;
a switching determination step of determining whether or not there is an air-fuel ratio mode switching request based on the air-fuel ratio mode selected in the air-fuel ratio mode setting step;
a reduced torque setting step of setting a torque reduction amount for reducing the torque generated by the engine, based on a steering angle of the steering wheel; and
a suppressing step of suppressing switching of the air-fuel ratio mode based on the switching request when it is determined in the switching determining step that there is a request for switching the air-fuel ratio mode when the torque reduction amount is set in the reduced torque setting step;
the engine is provided with a fuel injection valve,
the control method of the engine further includes:
an intake air amount increasing step of increasing the amount of intake air into the cylinder during switching from the second air-fuel ratio mode to the first air-fuel ratio mode;
a fuel increase step of controlling the fuel injection valve to increase the amount of fuel supplied into the cylinder in accordance with an increase in the intake air amount; and
a first retarding step of retarding an ignition timing of the ignition plug so that a torque generated by the engine becomes equal in response to an increase in the intake air amount.
4. The control method of an engine according to claim 3, characterized in that:
the suppressing in the suppressing step is to prohibit switching of the air-fuel ratio mode.
5. The control method of the engine according to claim 1 or 3, characterized by further comprising:
an intake air amount reducing step of reducing an amount of intake air into the cylinder in switching from the first air-fuel ratio mode to the second air-fuel ratio mode; and
a second retarding step of retarding an ignition timing of the ignition plug so that a torque generated by the engine becomes equal in response to a decrease in the intake air amount decreasing step.
6. The control method of the engine according to claim 1 or 3, characterized in that:
the reduction of the generated torque of the engine is realized by the retardation of the ignition timing of the spark plug.
7. The control method of the engine according to claim 1 or 3, characterized in that:
an air-fuel ratio range that does not belong to either one of the first air-fuel ratio range and the second air-fuel ratio range exists between a first air-fuel ratio range of the air-fuel mixture that is formed in the first air-fuel ratio mode and a second air-fuel ratio range of the air-fuel mixture that is formed in the second air-fuel ratio mode.
8. An engine system characterized by comprising:
an engine mounted on a vehicle having a steering wheel, mechanically coupled to a drive wheel of the vehicle, and including a spark plug;
an operating state sensor that detects an operating state of the engine;
a steering angle sensor that detects a steering angle of the steering wheel; and
a controller; wherein,
the controller selects a combustion mode of the engine between a first combustion mode in which all of the air-fuel mixture in a cylinder of the engine is combusted based on propagation of a flame generated by the ignition plug and a second combustion mode in which at least a part of the air-fuel mixture in the cylinder is combusted based on self-ignition, according to a detection result of the operating condition sensor,
the controller selects an air-fuel ratio mode between a first air-fuel ratio mode and a second air-fuel ratio mode depending on an operating state of the engine when the second combustion mode is selected as a combustion mode of the engine, the first air-fuel ratio mode being a mode in which the air-fuel mixture is leaner than a theoretical air-fuel ratio, the second air-fuel ratio mode being a mode in which the air-fuel mixture is equal to or richer than the theoretical air-fuel ratio,
the controller switches the air-fuel ratio mode according to the selected air-fuel ratio mode,
the controller sets a torque reduction amount for reducing the generated torque of the engine based on a detection result of the steering angle sensor,
the controller suppresses a decrease in the generated torque of the engine based on the set torque decrease amount when the air-fuel ratio mode is being switched,
the engine includes a fuel injection valve, and the controller increases an intake air amount into the cylinder during switching from the second air-fuel ratio mode to the first air-fuel ratio mode, controls the fuel injection valve to increase an amount of fuel supplied into the cylinder in accordance with the increase in the intake air amount, and retards an ignition timing of the ignition plug so that a torque generated by the engine becomes equal to the torque generated by the ignition plug in accordance with the increase in the intake air amount.
9. An engine system characterized by comprising:
an engine mounted on a vehicle having a steering wheel, mechanically coupled to a drive wheel of the vehicle, and including a spark plug;
an operating state sensor that detects an operating state of the engine;
a steering angle sensor that detects a steering angle of the steering wheel; and
a controller; wherein,
the controller selects a combustion mode of the engine between a first combustion mode in which all of the air-fuel mixture in a cylinder of the engine is combusted based on propagation of a flame generated by the ignition plug and a second combustion mode in which at least a part of the air-fuel mixture in the cylinder is combusted based on self-ignition, according to a detection result of the operating condition sensor,
the controller selects an air-fuel ratio mode between a first air-fuel ratio mode in which the air-fuel mixture is leaner than a theoretical air-fuel ratio and a second air-fuel ratio mode in which the air-fuel mixture is equal to or richer than the theoretical air-fuel ratio, depending on an operating state of the engine, when the second combustion mode is selected as a combustion mode of the engine,
the controller determines whether there is an air-fuel ratio mode switching request based on the selected air-fuel ratio mode,
the controller sets a torque reduction amount for reducing the generated torque of the engine based on a detection result of the steering angle sensor,
the controller suppresses switching of the air-fuel ratio mode based on the switching request when it is determined that there is a request for switching the air-fuel ratio mode when the torque reduction amount is set,
the engine includes a fuel injection valve, and the controller increases an intake air amount into the cylinder in switching from the second air-fuel ratio mode to the first air-fuel ratio mode, controls the fuel injection valve to increase an amount of fuel supplied into the cylinder in accordance with the increase in the intake air amount, and retards an ignition timing of the ignition plug so that a torque generated by the engine becomes an equal torque in accordance with the increase in the intake air amount.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2018-009079 | 2018-01-23 | ||
JP2018009079A JP6973111B2 (en) | 2018-01-23 | 2018-01-23 | Engine control method and engine system |
PCT/JP2019/001037 WO2019146462A1 (en) | 2018-01-23 | 2019-01-16 | Engine control method and engine system |
Publications (2)
Publication Number | Publication Date |
---|---|
CN111630262A CN111630262A (en) | 2020-09-04 |
CN111630262B true CN111630262B (en) | 2022-12-13 |
Family
ID=67395403
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201980009319.1A Active CN111630262B (en) | 2018-01-23 | 2019-01-16 | Engine control method and engine system |
Country Status (5)
Country | Link |
---|---|
US (1) | US11242817B2 (en) |
JP (1) | JP6973111B2 (en) |
CN (1) | CN111630262B (en) |
DE (1) | DE112019000484T5 (en) |
WO (1) | WO2019146462A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11441497B2 (en) * | 2018-01-23 | 2022-09-13 | Nissan Motor Co., Ltd. | Internal combustion engine control method and internal combustion engine control device |
JP7131170B2 (en) * | 2018-07-26 | 2022-09-06 | マツダ株式会社 | Compression ignition engine controller |
JP7131169B2 (en) * | 2018-07-26 | 2022-09-06 | マツダ株式会社 | Compression ignition engine controller |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6792344B2 (en) * | 1997-04-25 | 2004-09-14 | Hitachi, Ltd. | Automotive control apparatus and method |
JP3709652B2 (en) | 1997-05-13 | 2005-10-26 | 日産自動車株式会社 | Vehicle driving force control device |
JPH11157366A (en) | 1997-11-28 | 1999-06-15 | Mazda Motor Corp | Vehicle attitude control device |
JP2001073775A (en) | 1999-08-30 | 2001-03-21 | Nissan Motor Co Ltd | Compression ignition type internal combustion engine |
JP2006016973A (en) * | 2004-06-30 | 2006-01-19 | Mazda Motor Corp | Control device of cylinder injection internal combustion engine |
JP2010203271A (en) | 2009-03-02 | 2010-09-16 | Nissan Motor Co Ltd | Combustion control device of internal combustion engine |
CN102470719B (en) * | 2009-07-09 | 2015-03-25 | 丰田自动车株式会社 | Vehicular damping control system |
JP5870951B2 (en) * | 2013-03-25 | 2016-03-01 | マツダ株式会社 | Control device for spark ignition engine |
JP5994700B2 (en) | 2013-03-25 | 2016-09-21 | マツダ株式会社 | Control device for spark ignition engine |
JP5994701B2 (en) * | 2013-03-25 | 2016-09-21 | マツダ株式会社 | Control device for spark ignition engine |
JP6112304B2 (en) | 2013-10-31 | 2017-04-12 | マツダ株式会社 | Vehicle behavior control device |
JP6270244B2 (en) * | 2016-03-03 | 2018-01-31 | マツダ株式会社 | Engine control device |
JP6311739B2 (en) * | 2016-03-31 | 2018-04-18 | マツダ株式会社 | Engine control device |
JP6253000B1 (en) | 2016-09-14 | 2017-12-27 | マツダ株式会社 | Vehicle control device |
CN108138673B (en) * | 2016-09-09 | 2021-03-02 | 马自达汽车株式会社 | Vehicle control device |
JP7106993B2 (en) * | 2018-05-31 | 2022-07-27 | 株式会社デンソー | CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE AND CONTROL METHOD FOR INTERNAL COMBUSTION ENGINE |
-
2018
- 2018-01-23 JP JP2018009079A patent/JP6973111B2/en active Active
-
2019
- 2019-01-16 CN CN201980009319.1A patent/CN111630262B/en active Active
- 2019-01-16 WO PCT/JP2019/001037 patent/WO2019146462A1/en active Application Filing
- 2019-01-16 US US16/962,482 patent/US11242817B2/en active Active
- 2019-01-16 DE DE112019000484.0T patent/DE112019000484T5/en not_active Withdrawn
Also Published As
Publication number | Publication date |
---|---|
JP6973111B2 (en) | 2021-11-24 |
US20210079869A1 (en) | 2021-03-18 |
CN111630262A (en) | 2020-09-04 |
DE112019000484T5 (en) | 2020-10-22 |
WO2019146462A1 (en) | 2019-08-01 |
JP2019127868A (en) | 2019-08-01 |
US11242817B2 (en) | 2022-02-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN110067687B (en) | Engine control method and engine system | |
JP7077768B2 (en) | Compression ignition engine controller | |
JP7077769B2 (en) | Compression ignition engine controller | |
CN110067686B (en) | Engine control method and engine system | |
JP7047581B2 (en) | Compression ignition engine controller | |
JP7024586B2 (en) | Compression ignition engine controller | |
JP7077770B2 (en) | Compression ignition engine controller | |
JP7052536B2 (en) | Compression ignition engine controller | |
JP7047580B2 (en) | Compression ignition engine controller | |
JP7043960B2 (en) | Compression ignition engine controller | |
CN111630262B (en) | Engine control method and engine system | |
CN111670299B (en) | Engine control method and engine system | |
JP7024585B2 (en) | Compression ignition engine controller | |
JP7024584B2 (en) | Compression ignition engine controller | |
JP7043961B2 (en) | Compression ignition engine controller | |
JP6935783B2 (en) | Compression ignition engine controller | |
JP7052535B2 (en) | Compression ignition engine controller | |
JP7024587B2 (en) | Compression ignition engine controller | |
JP2020070770A (en) | Control device for engine | |
JP7239880B2 (en) | vehicle system | |
JP7088049B2 (en) | Compression ignition engine controller | |
JP7239881B2 (en) | vehicle system | |
JP2020176593A (en) | Control method and control device of engine | |
JP2020176595A (en) | Control method of engine and control device of engine | |
JP2020090893A (en) | Engine controller |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |